JSON数据交换、jsonString转jsonObject或jsonArray、json转string方法；string转json;

【JSON数据交换格式在系统间数据调用的处理】

public class Demo {
	
	public static void main(String[] args) {
		JSONArray tempJsonArray = null;
		Student student = null;//学生信息
		String interfaceName = "GetStudentScoreInfo";
		String targetAttribute = "studentInfo";
		//调用外部系统接口
		JSONObject remoteReturnJsonObject = studentService.getStudentScoreInfo(interfaceName, targetAttribute);
		boolean successFlag = remoteReturnJsonObject.getBoolean("success");// 调用接口是否成功
		if (successFlag) {
			tempJsonArray = parseTargetJsonObject(remoteReturnJsonObject,targetAttribute);
			if (null!=tempJsonArray&& tempJsonArray.size() > 0) {
				JSONObject tempJSONObject = (JSONObject) tempJsonArray.get(0);
				student = JSONObject.parseObject(tempJSONObject.toString(),Student.class);//映射为学生信息
			}
		}
	}

	/*
	 * 处理外部系统返回的JSON数据
	 */
	private  static JSONArray parseTargetJsonObject(JSONObject targetJsonObject, String method) {
		JSONArray jsonArray = null;//返回对象
		JSONObject jsonObject = null;
		if (targetJsonObject != null) {
			jsonObject = targetJsonObject.getJSONObject("responseData");
		}
		if (jsonObject != null) {
			jsonArray = jsonObject.getJSONArray(method);
		}
		return jsonArray;
	}
}

【jsonString转jsonObject或jsonArray】

package com.demo;
import java.lang.reflect.Field;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang.StringUtils;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;
import com.alibaba.fastjson.TypeReference;
public class Demo {
	public static void main(String[] args) throws Exception, Exception {
	String sourceJsonStr="{\"student\":[{\"countryName\":\"ZG\",\"departmentName\":\"Computer\",\"gradeName\":\"g3\",\"className\":\"c4\"},{\"countryName\":\"MG\",\"departmentName\":\"Electronic\",\"gradeName\":\"g2\",\"className\":\"c1\"},{\"countryName\":\"DG\",\"departmentName\":\"Math\",\"gradeName\":\"g4\",\"className\":\"c3\"}]}";
		//任务一、取数据集中的某个属性值
		JSONObject jsonObject=JSONObject.parseObject(sourceJsonStr);
		List<?> studentList=JSONArray.parseArray(jsonObject.getString("student"), Student.class);
		Object student=studentList.get(0);
		String departmentValue = org.apache.commons.beanutils.BeanUtils.getProperty(student, "departmentName");
		System.out.println("系别departmentName="+departmentValue);
		//任务二、转换数据集
		//编码映射处理前，打印studentList
    	for (Object stu : studentList) {
			System.out.println("输出stu="+stu.toString());
		}
		//字段值对应的编码映射
		String jsonObjectStr="{\"countryName\":{\"ZG\":\"中国\",\"MG\":\"美国\",\"DG\":\"德国\",\"ELSG\":\"俄罗斯\"},\"departmentName\":{\"Chinese\":\"中文系\",\"Foreign\":\"外文系\",\"Computer\":\"计算机系\",\"Electronic\":\"电子工程系\",\"Physics\":\"物理系\",\"Math\":\"数学系\"},\"gradeName\":{\"g1\":\"大学一年级\",\"g2\":\"大学二年级\",\"g3\":\"大学三年级\",\"g4\":\"大学四年级\"},\"className\":{\"c1\":\"1班\",\"c2\":\"2班\",\"c3\":\"3班\",\"c4\":\"4班\"}}";
        Map<String, String> targetMap = null;
        TypeReference<LinkedHashMap<String, String>> typeReference = new TypeReference<LinkedHashMap<String, String>>() {
        };
        if (StringUtils.isNotBlank(jsonObjectStr)) {
        	targetMap = JSONObject.parseObject(jsonObjectStr, typeReference);//Map<String, String>
        }
        if (null!=targetMap && targetMap.size() > 0) {
        	for (Object stu : studentList) {
	            for (Iterator<String> it = targetMap.keySet().iterator(); it.hasNext();) {
	            	String key = it.next();//如 department
	            	String keyJsonObjectValue = targetMap.get(key);//如 {"Electronic":"电子工程系","Foreign":"外文系","Physics":"物理系","Math":"数学系","Computer":"计算机系","Chinese":"中文系"}
//	            	System.out.println("对象名称key="+key);
//	            	System.out.println("对象值jsonObjectValue="+jsonObjectValue);
	            	String keyValue = org.apache.commons.beanutils.BeanUtils.getProperty(stu, key);//原始字符串里属性key对应的值 如：Computer
	                LinkedHashMap<String, String> codeMap = JSONObject.parseObject(keyJsonObjectValue, typeReference);//某种属性编码映射Map LinkedHashMap<String, String>
	                //
	                Field field = stu.getClass().getDeclaredField(key);
	                field.setAccessible(true);//不加该句将报错：can not access a member of class com.demo.Student with modifiers "private"
	                field.set(stu, codeMap.get(keyValue));
	            }
        	}
        	System.out.println("编码映射处理结束。。。");
        	//编码映射处理后，打印studentList
        	for (Object stu : studentList) {
				System.out.println("输出stu="+stu.toString());
			}
        }
	}
}

效果图：

二、
//json转string

function jsonToString (obj){   
        var THIS = this;    
        switch(typeof(obj)){   
            case 'string':   
                return '"' + obj.replace(/(["\\])/g, '\\$1') + '"';   
            case 'array':   
                return '[' + obj.map(THIS.jsonToString).join(',') + ']';   
            case 'object':   
                 if(obj instanceof Array){   
                    var strArr = [];   
                    var len = obj.length;   
                    for(var i=0; i<len; i++){   
                        strArr.push(THIS.jsonToString(obj[i]));   
                    }   
                    return '[' + strArr.join(',') + ']';   
                }else if(obj==null){   
                    return 'null';   
  
                }else{   
                    var string = [];   
                    for (var property in obj) string.push(THIS.jsonToString(property) + ':' + THIS.jsonToString(obj[property]));   
                    return '{' + string.join(',') + '}';   
                }   
            case 'number':   
                return obj;   
            case false:   
                return obj;   
        }   
    }

===========================================================

String arr=new String(request.getParameter("arr").getBytes("ISO8859-1"), "UTF-8");
var arr2='<%=arr%>';
		var list=eval('('+arr2+')');//用eval函数将json转化为对象  
		alert(list[0].fileName);
		alert(list[1].fileName);
		alert(list[2].fileName);