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接收、返回Json Day8 2018-11-26

接收、返回Json Day8 2018-11-26

作者: Ernest_Chou | 来源:发表于2018-11-26 23:50 被阅读0次

    4. json数据转换

    4.1 Jackson接收JSON格式数据

    4.1.1 pom.xml
    • 添加Jackson支持
    <!-- jackson -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.7</version>
    </dependency>
    
    4.1.2 springmvc-config.xml添加配置:
     <!-- 设置配置方案 自动注册RequestMappingHandlerMapping、RequestMappingHandlerAdapter-->
    <mvc:annotation-driven/>
    <!-- 使用默认的Servlet来响应静态文件 -->
    <mvc:default-servlet-handler/>
    
    • 说明
      <!-- 处理器映射器、处理器适配器不配置时,spring会使用默认配置处理请求 -->
      <!-- 主动配置,@Controller分发请求必须,并提供数据绑定支持@NumberFormannotation、@DataTime、@Valid、读写xml(JAXB)、读写json(默认Jackson) -->
      <!-- 配置annotation类型的处理映射器 -->
      <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping"/>
      <!-- 配置annotation类型的处理器适配器 -->
      <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter"/>
    
    • web.xml中配置的DispatchServlet会拦截所有请求url,而引入jsundefined<script type="text/javascript" src="../include/js/json3.min.js"></script>将所有“/”看成请求路径,会报404。当加上默认配置的Servlet时,Servlet找不到它时会去找静态的内容。
    4.1.3 @Controller
    @Controller
    @RequestMapping(value="/testRequestBody")
    public class RequestBodyTestController {
        private static final Log logger = LogFactory.getLog(RequestBodyTestController.class);
        
            
    //@RequestBody 根据json数据,转换成对于的Object
        @RequestMapping(value="/setJackson")
        public void setJackson(@RequestBody User user,HttpServletResponse response) throws IOException{
            //ObjectMapper 类是Jackson库的主要类。提供将Java对象转换成对于的JSON格式数据的功能
            ObjectMapper mapper = new  ObjectMapper();
            //将User对象转换为json输出
            logger.info(mapper.writeValueAsString(user));
            user.setUserName("测试JSON转换");
            response.setContentType("text/html;charset=UTF-8");
            response.getWriter().println(mapper.writeValueAsString(user));
        }
    }
    
    4.1.4 jsp
    <body>
        登录名:<span id="loginName"></span><br>
        密码:<span id="password"></span><br>
        用户名:<span id="userName"></span><br>
    </body>
    <script type="text/javascript" src="../include/js/jquery-3.3.1.min.js"></script>
    <script type="text/javascript" src="../include/js/json3.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
            testSetJackson();
        });
        function testSetJackson(){
            $.ajax("${pageContext.request.contextPath}/testRequestBody/setJackson",
                {
                    dataType:"json",
                    type:"post",
                    contentType:"application/json",
                    data:JSON.stringify({password:1,loginName:"spring MVC 企业应用实践setJackson"}),
                    async:true,
                    success:function(data){
                        console.log(data),
                        $("#loginName").html(data.loginName);
                        $("#password").html(data.password);
                        $("#userName").html(data.userName);
                    },
                    error:function(){
                        alert("数据发送失败!");
                    }
                    
                
            });
        }
    </script>
    

    4.2 FastJson接收JSON格式数据

    4.3.1 pom.xml
    • 添加Jackson支持
    <!--添加fastjson支持 -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>1.2.53</version>
    </dependency>
    
    4.1.2 springmvc-config.xml添加配置:
    • 使用第三方的fastjson处理json数据,需要配置HTTPMessageConverter
    <!-- 使用默认的Servlet来响应静态文件 -->
    <mvc:default-servlet-handler/>
    <!-- 设置配置方案 -->
    <mvc:annotation-driven>
        <!-- 设置不适用默认的消息转换器 -->
        <mvc:message-converters register-defaults="false">
            <!-- 配置spring的转换器 -->
            <bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter"/>
            <bean class="org.springframework.http.converter.BufferedImageHttpMessageConverter"/>
            <!-- 配置fastjson中实现HTTPMessageConverter接口的转换器 -->
            <!-- FastJsonHttpMessageConverter是fastjson中实现了HTTPMessageConverter接口的类 -->
            <bean id="fastJsonHttpMessageConverter"  class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
            <!-- 加入支持的媒体类型:返回contentType -->
                <property name="supportedMediaTypes">
                    <list>
                        <!-- 一定要先写text/html,不然IE下会出现下载提示 -->
                        <value>text/html;charset=UTF-8</value>
                        <value>application/json;charset=UTF-8</value>
                    </list>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>
    
    4.1.3 @Controller
    @Controller
    @RequestMapping(value="/testRequestBody")
    public class RequestBodyTestController {
        private static final Log logger = LogFactory.getLog(RequestBodyTestController.class);
        
        
    //@RequestBody 根据json数据,转换成对于的Object
    @RequestMapping(value="/setFastjson")
        public void setFastjson(@RequestBody User user,HttpServletResponse response) throws IOException{
            //JSONObject-lib是一个beans,collection是,maps,javaarrays和xml、json互相转换的包
            
            //使用JSONObject将User对象转换为json输出
            logger.info(JSONObject.toJSONString(user));
            user.setUserName("测试Fastjson转换");
            response.setContentType("text/html;charset=UTF-8");
            response.getWriter().println(JSONObject.toJSONString(user));
        }
    }
    
    4.1.4 jsp
    <body>
        登录名:<span id="loginName"></span><br>
        密码:<span id="password"></span><br>
        用户名:<span id="userName"></span><br>
    </body>
    <script type="text/javascript" src="../include/js/jquery-3.3.1.min.js"></script>
    <script type="text/javascript" src="../include/js/json3.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
            testSetFastjson();
        });
        function testSetFastjson(){
            $.ajax("${pageContext.request.contextPath}/testRequestBody/setFastjson",
                {
                    dataType:"json",
                    type:"post",
                    contentType:"application/json",
                    data:JSON.stringify({password:1,loginName:"spring MVC 企业应用实践setFastjson"}),
                    async:true,
                    success:function(data){
                        console.log(data),
                        $("#loginName").html(data.loginName);
                        $("#password").html(data.password);
                        $("#userName").html(data.userName);
                    },
                    error:function(){
                        alert("数据发送失败!");
                    }
                    
                
            });
        }
    </script>
    

    4.3 Jackson返回JSON格式数据

    4.3.1 pom.xml
    • 同 4.1.1
    4.3.2 springmvc-config.xml配置
    • 同4.1.2
    4.3.3 @Controller
    @Controller
    @RequestMapping(value="/testResponseBody")
    public class ResponseBodyTestController {
        
        
        @RequestMapping(value="/getJackson")
        @ResponseBody//将集合数据转换为json格式并将其返回客户端
        public Object getJackson() {
            List<User> list = new ArrayList<User>();
            list.add(new User("shi_yue", "1Jackson", "石悦"));
            list.add(new User("shi_lili", "2Jackson", "石丽丽"));
            return list;
        }
        
    }
    
    4.3.4 jsp
    <body>
        <table id="userTable" border="1" style="border-collapse: collapse;">
            <tr>
                <th>登录名</th>
                <th>密码</th>
                <th>用户名</th>
            </tr>
        </table>
    </body>
    <script type="text/javascript" src="../include/js/jquery-3.3.1.min.js"></script>
    <script type="text/javascript" src="../include/js/json3.min.js"></script>
    <script type="text/javascript">
        $(document).ready(function(){
            testResponeBody();
        });
        function testResponeBody(){
            $.post("${pageContext.request.contextPath}/testResponseBody/getJackson",null,
                    function(data){
                        $.each(data,function(){
                            var tr = $("<tr align='center' />");
                            $("<td/>").html(this.loginName).appendTo(tr);
                            $("<td/>").html(this.password).appendTo(tr);
                            $("<td/>").html(this.userName).appendTo(tr);
                            $("#userTable").append(tr);
                        })
                    },
                "json");
        }
    </script>
    

    4.4 自定义HttpMessageConverter返回JSON格式数据

    4.4.1 pom.xml
    • 同 4.2.1
    4.4.2 springmvc-config.xml配置
    • 同4.2.2
    4.4.3 @Controller
    • 同 4.3.3
    4.4.4 @jsp
    • 同 4.3.4

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          本文标题:接收、返回Json Day8 2018-11-26

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