常用的java类型转json的转换类

公司不准引入json-lib-2.x.jar所以只好自己写了一个基本类型的object转json的类，然后支持8种基本类型和javabean，list，map，array，使用putJSON方法，key值随便写，value是要转换的对象。

JsonObjectConvert.java:

package com.pz.util;

import java.lang.reflect.Field;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

public class JsonObjectConvert {

    private StringBuffer sf = null;

    public  String SimpleObjectToJson(Object o){

        sf = new StringBuffer("{");

        //sf.append(o.getClass().getSimpleName());
        Field field[] = o.getClass().getDeclaredFields();
        String content = "";
        for(Field f : field ){
            try {
                f.setAccessible(true);
                content += "\"" + f.getName() + "\":\"" + convertNull(f.get(o)) +"\",";
            } catch (IllegalArgumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IllegalAccessException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        sf.append(content);
        return sf.toString().substring(0, sf.length() - 1) + "}";
    }
    public Object convertNull(Object o){
        if(o == null){
            return "";
        }else {
            return o;
        }
    }
    @SuppressWarnings("unchecked")
    public  Object convertJSON(Object o){
        if(o == null){
            return "";
        }else if(o instanceof Boolean){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Character){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Short){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Integer){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Long){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Float){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Double){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Byte){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof List){
            return listToJSON((List)o);
        }else if(o instanceof Map){
            return mapToJSON((Map)o);
        }else if(o.getClass().isArray()){
            return arrayToJSON(o);
        }else if(o instanceof String){
            return "\"" +o.toString() + "\"";
        }else if(o instanceof Date){
            return "\"" +o.toString() + "\"";
        }
        return SimpleObjectToJson(o);
    }
    @SuppressWarnings("unchecked")
    public  String listToJSON(List list){
        sf = new StringBuffer("[");
        for(int i = 0;i < list.size();i++){
            sf.append( convertJSON(list.get(i)) + ",");
        }
        return sf.toString().substring(0,sf.toString().length() - 1) + "]";
    }
    @SuppressWarnings("unchecked")
    public  String mapToJSON(Map map){
        sf = new StringBuffer("[");
        Iterator ite = map.entrySet().iterator();
        while(ite.hasNext()){
            Entry o = (Entry)ite.next();
            String key = convertJSON(o.getKey()).toString();
            sf.append("{\"" + key.substring(1, key.length() - 1) + "\":");
            sf.append(convertJSON(o.getValue()) +"},");
        }
        return sf.toString().substring(0,sf.toString().length() - 1) + "]";
    }
    public String arrayToJSON(Object o){
        sf = new StringBuffer("[");
        Object[] obj = (Object[])o;
        for(int i = 0;i < obj.length;i++){
            sf.append(convertJSON(obj[i]) + ",");
        }
        return sf.toString().substring(0, sf.toString().length() - 1) + "]";
    }
    //the sum method convert to json key --> value
    public static String putJSON(String key,Object value){
        JsonObjectConvert joc = new JsonObjectConvert();
        String jsonString = "{\"" + key + "\":" + joc.convertJSON(value) + "}";
        return jsonString;
    }
}

package com.pz.util;

import java.lang.reflect.Field;import java.util.Date;import java.util.Iterator;import java.util.List;import java.util.Map;import java.util.Map.Entry;
public class JsonObjectConvert {private StringBuffer sf = null;public  String SimpleObjectToJson(Object o){sf = new StringBuffer("{");//sf.append(o.getClass().getSimpleName());Field field[] = o.getClass().getDeclaredFields();String content = "";for(Field f : field ){try {f.setAccessible(true);content += "\"" + f.getName() + "\":\"" + convertNull(f.get(o)) +"\",";} catch (IllegalArgumentException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (IllegalAccessException e) {// TODO Auto-generated catch blocke.printStackTrace();}}sf.append(content);return sf.toString().substring(0, sf.length() - 1) + "}";}public Object convertNull(Object o){if(o == null){return "";}else {return o;}}@SuppressWarnings("unchecked")public  Object convertJSON(Object o){if(o == null){return "";}else if(o instanceof Boolean){return "\"" +o.toString() + "\"";}else if(o instanceof Character){return "\"" +o.toString() + "\"";}else if(o instanceof Short){return "\"" +o.toString() + "\"";}else if(o instanceof Integer){return "\"" +o.toString() + "\"";}else if(o instanceof Long){return "\"" +o.toString() + "\"";}else if(o instanceof Float){return "\"" +o.toString() + "\"";}else if(o instanceof Double){return "\"" +o.toString() + "\"";}else if(o instanceof Byte){return "\"" +o.toString() + "\"";}else if(o instanceof List){return listToJSON((List)o);}else if(o instanceof Map){return mapToJSON((Map)o);}else if(o.getClass().isArray()){return arrayToJSON(o);}else if(o instanceof String){return "\"" +o.toString() + "\"";}else if(o instanceof Date){return "\"" +o.toString() + "\"";}return SimpleObjectToJson(o);}@SuppressWarnings("unchecked")public  String listToJSON(List list){sf = new StringBuffer("[");for(int i = 0;i < list.size();i++){sf.append( convertJSON(list.get(i)) + ",");}return sf.toString().substring(0,sf.toString().length() - 1) + "]";}@SuppressWarnings("unchecked")public  String mapToJSON(Map map){sf = new StringBuffer("[");Iterator ite = map.entrySet().iterator();while(ite.hasNext()){Entry o = (Entry)ite.next();String key = convertJSON(o.getKey()).toString();sf.append("{\"" + key.substring(1, key.length() - 1) + "\":");sf.append(convertJSON(o.getValue()) +"},");}return sf.toString().substring(0,sf.toString().length() - 1) + "]";}public String arrayToJSON(Object o){sf = new StringBuffer("[");Object[] obj = (Object[])o;for(int i = 0;i < obj.length;i++){sf.append(convertJSON(obj[i]) + ",");}return sf.toString().substring(0, sf.toString().length() - 1) + "]";}//the sum method convert to json key --> valuepublic static String putJSON(String key,Object value){JsonObjectConvert joc = new JsonObjectConvert();String jsonString = "{\"" + key + "\":" + joc.convertJSON(value) + "}"; return jsonString;}}