web服务端使用JSONArrayy或JSONObject转json字符串为Java对象或数组

由于项目中需要使用webSocket向各个组件传递json消息格式如[{"parameter":JSON.stringify("需要发送的消息"),"targetId":"目标webSocket的id"}]，
在服务端将json数据转换为对象数组，对每个对象获取“parameter”以及”targetId”。然后遍历websocket集合查找与”targetId”相同的目标发送”parameter”。
当中转json字符串为Java对象或数组需要使用JSONArrayy或JSONObject，利用maven导jar包时可用json-lib

<!-- https://mvnrepository.com/artifact/net.sf.json-lib/json-lib --><dependency>    <groupId>net.sf.json-lib</groupId>    <artifactId>json-lib</artifactId>    <version>2.4</version>    <classifier>jdk15</classifier></dependency>

要利用这个jar包时需要依赖另外5个jar包如下

<!-- https://mvnrepository.com/artifact/commons-beanutils/commons-beanutils --><dependency>    <groupId>commons-beanutils</groupId>    <artifactId>commons-beanutils</artifactId>    <version>1.8.0</version></dependency><!-- https://mvnrepository.com/artifact/commons-collections/commons-collections --><dependency>    <groupId>commons-collections</groupId>    <artifactId>commons-collections</artifactId>    <version>3.2.1</version></dependency><!-- https://mvnrepository.com/artifact/commons-lang/commons-lang --><dependency>    <groupId>commons-lang</groupId>    <artifactId>commons-lang</artifactId>    <version>2.5</version></dependency><!-- https://mvnrepository.com/artifact/commons-logging/commons-logging --><dependency>    <groupId>commons-logging</groupId>    <artifactId>commons-logging</artifactId>    <version>1.1.1</version></dependency><!-- https://mvnrepository.com/artifact/net.sf.ezmorph/ezmorph --><dependency>    <groupId>net.sf.ezmorph</groupId>    <artifactId>ezmorph</artifactId>    <version>1.0.6</version></dependency>

以上各jar包都为必须，版本可更改但需要注意不冲突，如果使用Intellij idea的话可以用Maven Helper插件查看Maven dependency tree或是查找冲突。

测试时自定义Student类如：
public class Student {
//姓名
private String name;
//年龄
private String age;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAge() {
return age;
}
public void setAge(String age) {
this.age = age;
}
@Override
public String toString() {
return “Student [name=” + name + “, age=” + age + “]”;
}

测试代码如：

String arrayStr="[{\"name\":\"Song\",\"age\":\"22\"}]";JSONArray jsonArray=JSONArray.fromObject(arrayStr);Object o=jsonArray.get(0);JSONObject jsonObject=JSONObject.fromObject(o);Student stu=(Student)JSONObject.toBean(jsonObject, Student.class);System.out.println("stu:"+stu);

输出结果：stu:Student [name=Song, age=22]

当时陷入了一个小坑，当代码采用Java Application跑时正确无误，但是当采用Tomcat Server跑时则异常终止，报错如：

18-Jul-2017 23:31:53.326 严重 [http-nio-8081-exec-7] org.apache.tomcat.websocket.pojo.PojoEndpointBase.onError No error handling configured for [websockets.MyWebSocket] and the following error occurred java.lang.RuntimeException: org/apache/commons/lang/exception/NestableRuntimeException

解决办法是根据“org/apache/commons/lang/exception/NestableRuntimeException”将当中maven下的commons-lang-2.5.jar复制到tomcat下lib目录中测试运行如果还有报错则继续复制相关jar包。

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