为什么 com.google.code.gson 包无法从 Postman 发送到 Tomcat 的 json 字符串正确转换 java.sql.Timestamp 的值？

问题描述 投票：0回答：1

我做什么？

我从 

GET
向 
Postman
发送了 
Tomcat v9.0
请求，其中包含以下数据。

{
    "diaryId":2,
    "userId":2,
    "createTimestamp":"2022-05-05 12:00:00",  
    "totalFat":2.52,
    "totalCarbon":2.3,
    "totalProtein":2.1,
    "totalFiber":2.1,
    "totalSugar":1.2,
    "totalSodium":1.1,
    "totalCalories":1.21 
}

如下图。

GET request from Postman to Tomcat v9.0

为什么在我运行 Tomcat 服务器然后使用 

GET
方法并使用 
http://localhost:8080/HealthHelper/dietDiary/test
给定 url 
Postman
发送请求后，Eclipse IDE 中的控制台会打印以下输出？

Ready to deserialize.
dietDiary2:DietDiary2 [diaryId=2, userId=2, createTimestamp=2021-12-26 00:00:00.0, totalFat=2.52, totalCarbon=2.3, totalProtein=2.1, totalFiber=2.1, totalSugar=1.2, totalSodium=1.1, totalCalories=1.21]

我做错了什么吗？

欣赏

任何有关此问题的回复都将受到高度赞赏。

代码

/HealthHelper/src/main/java/controller/TestController.java

使用Eclipse IDE，我在

/HealthHelper/src/main/java/controller/TestController.java
中用Java编写了Servlet代码，其中有一个带有部分url的WebServlet注释
/dietDiary/test
-- 
@WebServlet("/dietDiary/test")
，如下所示。

package controller;

import java.io.IOException;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import constant.DatePattern;
import vo.DietDiary2;

@WebServlet("/dietDiary/test")
public class TestController extends HttpServlet {
    
    private static final long serialVersionUID = 1L;
    
    @Override 
    protected void doGet(HttpServletRequest req,HttpServletResponse res) throws IOException{
        GsonBuilder gsonBuilder = new GsonBuilder();
        gsonBuilder
            .setDateFormat(DatePattern.datePattern);
        Gson gson = gsonBuilder.create();
        System.out.println("Ready to deserialize.");
        DietDiary2 dietDiary2 = gson.fromJson(req.getReader(), DietDiary2.class);
        System.out.println("dietDiary2:"+dietDiary2.toString());
    }
}


/HealthHelper/src/main/java/constant/DatePattern.java

package constant;

public class DatePattern {
    public final static String datePattern = "YYYY-MM-DD hh:mm:ss";
}


/HealthHelper/src/main/java/vo/DietDiary2.java

在

/HealthHelper/src/main/java/vo/DietDiary2.java
中，有
DietDiary2
满足JavaBean规则的公共类，如下所示。

请注意，我使用 

java.sql.Timestamp
类来存储 
Timestamp
。

package vo;

import java.sql.Timestamp;

public class DietDiary2 {
    private int diaryId;
    private int userId;
    private Timestamp createTimestamp;
    private Double totalFat;
    private Double totalCarbon;
    private Double totalProtein;
    private Double totalFiber;
    private Double totalSugar;
    private Double totalSodium;
    private Double totalCalories;
    
    public int getDiaryId() {
        return diaryId;
    }
    public void setDiaryId(int diaryId) {
        this.diaryId = diaryId;
    }
    public int getUserId() {
        return userId;
    }
    public void setUserId(int userId) {
        this.userId = userId;
    }
    
    public Timestamp getCreateTimestamp() {
        return createTimestamp;
    }
    public void setCreateTimestamp(Timestamp createTimestamp) {
        this.createTimestamp = createTimestamp;
    }
    
    public Double getTotalFat() {
        return totalFat;
    }
    public void setTotalFat(Double totalFat) {
        this.totalFat = totalFat;
    }
    public Double getTotalCarbon() {
        return totalCarbon;
    }
    public void setTotalCarbon(Double totalCarbon) {
        this.totalCarbon = totalCarbon;
    }
    public Double getTotalProtein() {
        return totalProtein;
    }
    public void setTotalProtein(Double totalProtein) {
        this.totalProtein = totalProtein;
    }
    public Double getTotalFiber() {
        return totalFiber;
    }
    public void setTotalFiber(Double totalFiber) {
        this.totalFiber = totalFiber;
    }
    public Double getTotalSugar() {
        return totalSugar;
    }
    public void setTotalSugar(Double totalSugar) {
        this.totalSugar = totalSugar;
    }
    public Double getTotalSodium() {
        return totalSodium;
    }
    public void setTotalSodium(Double totalSodium) {
        this.totalSodium = totalSodium;
    }
    public Double getTotalCalories() {
        return totalCalories;
    }
    public void setTotalCalories(Double totalCalories) {
        this.totalCalories = totalCalories;
    }
    
    public boolean equals(Object object) {
        if(object instanceof DietDiary2) {
            return false;
        }
        
        DietDiary2 dietDiary = (DietDiary2) object;
        
        if(!(this.getDiaryId() == dietDiary.getDiaryId())) {
            return false;
        }
        
        if(!(this.getUserId() == dietDiary.getUserId())) {
            return false;
        }
        
        if(!(this.getCreateTimestamp() == dietDiary.getCreateTimestamp())) {
            return false;
        }
        
        return true;
    }
    @Override
    public String toString() {
        return "DietDiary2 [diaryId=" + diaryId + ", userId=" + userId + ", createTimestamp=" + createTimestamp
                + ", totalFat=" + totalFat + ", totalCarbon=" + totalCarbon + ", totalProtein=" + totalProtein
                + ", totalFiber=" + totalFiber + ", totalSugar=" + totalSugar + ", totalSodium=" + totalSodium
                + ", totalCalories=" + totalCalories + "]";
    }

    
}

Eclipse IDE 控制台中的信息。

开始执行
Tomcat v9.0
时在控制台显示信息。

Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version name:   Apache Tomcat/9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          May 3 2024 20:22:11 UTC
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version number: 9.0.89.0
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Windows 11
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            10.0
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          amd64
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             C:\Users\Jay\.p2\pool\plugins\org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706\jre
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           23+37
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Eclipse Adoptium
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dwtp.deploy=C:\apache-tomcat-9.0.89\webapps
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.lang=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.io=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.util=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.util.concurrent=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dfile.encoding=UTF-8
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dstdout.encoding=UTF-8
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dstderr.encoding=UTF-8
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -XX:+ShowCodeDetailsInExceptionMessages
Oct 26, 2024 8:57:50 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The Apache Tomcat Native library which allows using OpenSSL was not found on the java.library.path: [C:\Users\Jay\.p2\pool\plugins\org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706\jre\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Users/Jay/.p2/pool/plugins/org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706/jre/bin/server;C:/Users/Jay/.p2/pool/plugins/org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706/jre/bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\NVIDIA Corporation\NVIDIA NvDLISR;C:\ProgramData\chocolatey\bin;C:\Program Files\Git\cmd;C:\Users\Jay\.jdks\openjdk-23\bin;C:\Users\Jay\AppData\Local\Microsoft\WindowsApps;C:\Users\Jay\AppData\Local\Programs\Microsoft VS Code\bin;C:\Users\Jay\.jdks\openjdk-23\bin;;C:\Windows\System32;;.]
Oct 26, 2024 8:57:50 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-8080"]
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.Catalina load
INFO: Server initialization in [486] milliseconds
Oct 26, 2024 8:57:51 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service [Catalina]
Oct 26, 2024 8:57:51 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet engine: [Apache Tomcat/9.0.89]
Oct 26, 2024 8:57:51 PM org.apache.tomcat.util.descriptor.web.WebXml setVersion
WARNING: Unknown version string [5.0]. Default version will be used.
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Oct 26, 2024 8:57:52 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\BookshopDemo_Server]
Oct 26, 2024 8:57:52 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\BookshopDemo_Server] has finished in [38] ms
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\docs]
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\docs] has finished in [15] ms
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\examples]
Oct 26, 2024 8:57:52 PM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: contextInitialized()
Oct 26, 2024 8:57:52 PM org.apache.catalina.core.ApplicationContext log
INFO: SessionListener: contextInitialized()
Oct 26, 2024 8:57:52 PM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: attributeAdded('StockTicker', 'async.Stockticker@619f2afc')
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\examples] has finished in [196] ms
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\FCMDemo_Server]
Oct 26, 2024 8:57:53 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\FCMDemo_Server] has finished in [1,435] ms
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\host-manager]
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\host-manager] has finished in [15] ms
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\manager]
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\manager] has finished in [13] ms
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\ROOT]
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\ROOT] has finished in [10] ms
Oct 26, 2024 8:57:54 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
Oct 26, 2024 8:57:54 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in [3024] milliseconds
发送带有 url

GET
 和
http://localhost:8080/HealthHelper/dietDiary/test
 的
Postman
 请求后控制台中的
信息。

Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version name:   Apache Tomcat/9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built:          May 3 2024 20:22:11 UTC
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version number: 9.0.89.0
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name:               Windows 11
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version:            10.0
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture:          amd64
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home:             C:\Users\Jay\.p2\pool\plugins\org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706\jre
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version:           23+37
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor:            Eclipse Adoptium
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:         C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME:         C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.base=C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=C:\apache-tomcat-9.0.89
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dwtp.deploy=C:\apache-tomcat-9.0.89\webapps
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.lang=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.io=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.util=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.util.concurrent=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.rmi/sun.rmi.transport=ALL-UNNAMED
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dfile.encoding=UTF-8
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dstdout.encoding=UTF-8
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dstderr.encoding=UTF-8
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -XX:+ShowCodeDetailsInExceptionMessages
Oct 26, 2024 8:57:50 PM org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The Apache Tomcat Native library which allows using OpenSSL was not found on the java.library.path: [C:\Users\Jay\.p2\pool\plugins\org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706\jre\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:\Windows;C:/Users/Jay/.p2/pool/plugins/org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706/jre/bin/server;C:/Users/Jay/.p2/pool/plugins/org.eclipse.justj.openjdk.hotspot.jre.full.win32.x86_64_23.0.0.v20240919-1706/jre/bin;C:\Windows\system32;C:\Windows;C:\Windows\System32\Wbem;C:\Windows\System32\WindowsPowerShell\v1.0\;C:\Windows\System32\OpenSSH\;C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files\NVIDIA Corporation\NVIDIA NvDLISR;C:\ProgramData\chocolatey\bin;C:\Program Files\Git\cmd;C:\Users\Jay\.jdks\openjdk-23\bin;C:\Users\Jay\AppData\Local\Microsoft\WindowsApps;C:\Users\Jay\AppData\Local\Programs\Microsoft VS Code\bin;C:\Users\Jay\.jdks\openjdk-23\bin;;C:\Windows\System32;;.]
Oct 26, 2024 8:57:50 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-8080"]
Oct 26, 2024 8:57:50 PM org.apache.catalina.startup.Catalina load
INFO: Server initialization in [486] milliseconds
Oct 26, 2024 8:57:51 PM org.apache.catalina.core.StandardService startInternal
INFO: Starting service [Catalina]
Oct 26, 2024 8:57:51 PM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet engine: [Apache Tomcat/9.0.89]
Oct 26, 2024 8:57:51 PM org.apache.tomcat.util.descriptor.web.WebXml setVersion
WARNING: Unknown version string [5.0]. Default version will be used.
SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
Oct 26, 2024 8:57:52 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\BookshopDemo_Server]
Oct 26, 2024 8:57:52 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\BookshopDemo_Server] has finished in [38] ms
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\docs]
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\docs] has finished in [15] ms
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\examples]
Oct 26, 2024 8:57:52 PM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: contextInitialized()
Oct 26, 2024 8:57:52 PM org.apache.catalina.core.ApplicationContext log
INFO: SessionListener: contextInitialized()
Oct 26, 2024 8:57:52 PM org.apache.catalina.core.ApplicationContext log
INFO: ContextListener: attributeAdded('StockTicker', 'async.Stockticker@619f2afc')
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\examples] has finished in [196] ms
Oct 26, 2024 8:57:52 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\FCMDemo_Server]
Oct 26, 2024 8:57:53 PM org.apache.jasper.servlet.TldScanner scanJars
INFO: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\FCMDemo_Server] has finished in [1,435] ms
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\host-manager]
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\host-manager] has finished in [15] ms
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\manager]
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\manager] has finished in [13] ms
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory [C:\apache-tomcat-9.0.89\webapps\ROOT]
Oct 26, 2024 8:57:53 PM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deployment of web application directory [C:\apache-tomcat-9.0.89\webapps\ROOT] has finished in [10] ms
Oct 26, 2024 8:57:54 PM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-nio-8080"]
Oct 26, 2024 8:57:54 PM org.apache.catalina.startup.Catalina start
INFO: Server startup in [3024] milliseconds
Ready to deserialize.
dietDiary2:DietDiary2 [diaryId=2, userId=2, createTimestamp=2021-12-26 00:00:00.0, totalFat=2.52, totalCarbon=2.3, totalProtein=2.1, totalFiber=2.1, totalSugar=1.2, totalSodium=1.1, totalCalories=1.21]

其他信息

我在本节中总结了其他信息（其中大部分都在上面提到过）。

服务器

后端服务器

Tomcat v9.0 (version 9.0)

Tomcat 设置概述

  1. 版本是9.0
  2. IP地址是
    localhost
  3. 端口号为 
    8080
    （Tomcat 中的默认端口号）。

Overview of settings about Tomcat

前端服务器

Postman
。我使用 Postman 来测试 Servlet。

请求
网址

http://localhost:8080/HealthHelper/dietDiary/test

方法

GET

IDE

Eclipse

编程语言

Java

HealthHelper 项目下的参考图书馆

Referenced Library

我尝试了什么？

我已检查这些设置是否正确。

  1. 请求网址：

关于信息，见上文。

  1. 请求的方法与
    javax.servlet
    中的方法匹配。

使用 

GET
方法发送请求，当 url 匹配时将调用 
doGet
方法（参见第 1 点）

此外，我已阅读这些文档。

  1. javax.servlet.http.HttpServlet 类

  2. 关于

    setDateFormat
    类中
    com.google.gson.GsonBuilder
    非静态方法的API

我期待什么？

从服务器接收到的

createTimestamp
的值（这里是
Postman
）与服务器发送过来的json字符串中的key
createTimestamp
对应的值一致。

更准确地说，我预料到了

Eclipse 中的控制台打印

Ready to deserialize.
dietDiary2:DietDiary2 [diaryId=2, userId=2, createTimestamp=2022-05-05 12:00:00, totalFat=2.52, totalCarbon=2.3, totalProtein=2.1, totalFiber=2.1, totalSugar=1.2, totalSodium=1.1, totalCalories=1.21]

当发送带有以下数据的请求时。

{
    "diaryId":2,
    "userId":2,
    "createTimestamp":"2022-05-05 12:00:00",  
    "totalFat":2.52,
    "totalCarbon":2.3,
    "totalProtein":2.1,
    "totalFiber":2.1,
    "totalSugar":1.2,
    "totalSodium":1.1,
    "totalCalories":1.21 
}
json tomcat servlets gson sql-timestamp
1个回答
0
投票

我知道为什么吗？

setDateFormat
GsonBuilder
课程中将为 
java.util.Date
设置日期格式。

发帖后，我又仔细阅读了setDateFormat

类
中的
API
GsonBuilder，终于在下图中找到了线索。

！[关于 

setDateFormat
类中的 API 
GsonBuilder
的信息]]2

我单击带有日期文本的链接，它会重定向到有关 java.util.Date.

的网站。

证明我的猜测是正确的。我尝试用手写一些代码。

首先，我创建一个文件

DietDiary3.java
。然后从
DietDiary2.java
复制并粘贴。之后，我将名为 
createTimestamp
的字段类型从 
java.sql.Timestamp
更改为 
java.util.Date
如下

公开课

DietDiary2
在
DietDiary2.java

private Timestamp createTimestamp;

到

公开课

DietDiary3
在
DietDiary3.java

private Date createTimestamp;

其次，我重构了 getter、setter 和 

toString
方法。

第三，我在测试文件中使用 

DietDiary3
代替 
DietDiary2
-- 
/HealthHelper/src/main/java/controller/TestController.java

做到了

package controller;

import java.io.IOException;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

import constant.DatePattern;
import vo.DietDiary2;
import vo.DietDiary3;

@WebServlet("/dietDiary/test")
public class TestController extends HttpServlet {
    
    private static final long serialVersionUID = 1L;
    
    @Override 
    protected void doGet(HttpServletRequest req,HttpServletResponse res) throws IOException{
        GsonBuilder gsonBuilder = new GsonBuilder();
        gsonBuilder
            .setDateFormat(DatePattern.datePattern);
        Gson gson = gsonBuilder.create();
        System.out.println("Ready to deserialize.");
        DietDiary3 dietDiary3 = gson.fromJson(req.getReader(), DietDiary3.class);
        System.out.println("dietDiary3:"+dietDiary3.toString());
        Date createTimestamp = dietDiary3.getCreateTimestamp();
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat(DatePattern.datePattern);
        System.out.printf("simpleDateFormat.format(%s):%s.%n",createTimestamp,simpleDateFormat.format(createTimestamp));
    }
}

最后，我保存它并运行 

Tomcat
，然后再次发送请求（使用 
Postman
）。

我在 Eclipse 打印中看到了控制台

Ready to deserialize.
dietDiary3:DietDiary3 [diaryId=2, userId=2, createTimestamp=Sun Dec 26 00:00:00 CST 2021, totalFat=2.52, totalCarbon=2.3, totalProtein=2.1, totalFiber=2.1, totalSugar=1.2, totalSodium=1.1, totalCalories=1.21]
simpleDateFormat.format(Sun Dec 26 00:00:00 CST 2021):2022-12-360 12:00:00.

与请求中 json 字符串中名为 

createTimestamp
的键对应的值一致。

createTimestamp":"2022-05-05 12:00:00",
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