gpt4 book ai didi

json - Jackson @JsonView 没有按预期工作

转载 作者:行者123 更新时间:2023-12-01 05:21:56 28 4
gpt4 key购买 nike

我将 Jackson JSON 1.9.12 与 SpringMVC 一起使用。我创建了一个带有 JSON 字段的 dto。我想要两个具有不同 JSON 字段的相同 dto 配置文件,因此我创建了两个接口(interface)并使用 @JsonView 注释字段注解。

class Views {
static class Public {}
static class ExtendedPublic {}
...
}

public class Thing {
@JsonView(Views.Public.class) Integer id;
@JsonView(Views.ExtendPublic.class) String name;
}

在 Controller 中
@RequestMapping(value = "/thing/{id}")
public void getThing(@PathVariable final String id, HttpServletResponse response) {
Thing thing = new Thing();
ObjectMapper objectMapper = new ObjectMapper();
String json = objectMapper.writerWithView(Views.Public.class).writeValueAsString(thing);
LOG.debug("JSON: {}", json);
}

我希望 JSON 只包含“id”字段,但它总是包含所有字段。

有任何想法吗?

最佳答案

以下代码使用 Spring 3.2.0 和 Jackson 1.9.12 进行测试,仅返回 {id: 1}而不是扩展的 {name: "name"}因为它使用 .writerWithView(Views.Public.class)。切换到 Views.ExtendPublic.class 将导致 {"id":1,"name":"name"}
编辑:添加所有项目文件以获得完整的解决方案,使其成为比我在 Using @JsonView with Spring MVC 上的另一个更好的答案

DemoController.java

package com.demo.app;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.codehaus.jackson.map.annotate.JsonView;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.ObjectWriter;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Controller
public class DemoController {
private final ObjectMapper objectMapper = new ObjectMapper();

@RequestMapping(value="/jsonOutput")
@ResponseBody
public String myObject(HttpServletResponse response) throws IOException {
ObjectWriter objectWriter = objectMapper.writerWithView(Views.Public.class);
return objectWriter.writeValueAsString(new MyObject());
}

public static class Views {
static class Public {}
static class ExtendPublic extends Public {}
}

public class MyObject {
@JsonView(Views.Public.class) Integer id = 1;
@JsonView(Views.ExtendPublic.class) String name = "name";
}
}

web.xml
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0"/>

初始化程序.java
package com.demo.app.spring;

import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.servlet.DispatcherServlet;
import javax.servlet.*;

public class Initializer implements WebApplicationInitializer {
public void onStartup(ServletContext servletContext) throws ServletException {
AnnotationConfigWebApplicationContext mvcContext = new AnnotationConfigWebApplicationContext();
mvcContext.register(AppConfig.class);

ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher", new DispatcherServlet(mvcContext));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/*");
}
}

AppConfig.java
package com.demo.app.spring;

import org.springframework.context.annotation.*;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan(basePackages="com.demo.app")
public class AppConfig {
}

pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.demo</groupId>
<artifactId>app</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>${project.artifactId}</name>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<spring.version>3.2.0.RELEASE</spring.version>
<jetty.plugin.version>8.1.7.v20120910</jetty.plugin.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
<version>1.9.12</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.12</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>jetty-maven-plugin</artifactId>
<version>${jetty.plugin.version}</version>
<configuration>
<webApp>
<contextPath>/</contextPath>
</webApp>
</configuration>
</plugin>
</plugins>
</build>
</project>

在以下结构中:
pom.xml
src
|- main
|- java
| |- com
| |- demo
| |- app
| |- controller/DemoController.java
| |- spring/AppConfig.java, Initializer.java
|- webapp
|- WEB-INF/web.xml

关于json - Jackson @JsonView 没有按预期工作,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/15973141/

28 4 0
Copyright 2021 - 2024 cfsdn All Rights Reserved 蜀ICP备2022000587号
广告合作:1813099741@qq.com 6ren.com