android json转字串 android string转json

import java.lang.reflect.Field;
import java.util.List;
/**
 * List<String> 转换成'',格式的字符串输出
 * @author Administrator
 *
 */
public class ToStringUtils {
	
	/**
	 * Object To json String
	 * 
	 * @param obj
	 * 
	 * @return json String
	 */
	public static String objToJsonString(Object obj) {
	     
	    // 初始化返回值
	    String json = "str_empty";
	 
	    if (obj == null) {
	        return json;
	    }
	 
	    StringBuilder buff = new StringBuilder();
	    Field[] fields = obj.getClass().getFields();
	    try {
	        buff.append("[");
	        buff.append("{");
	        int i = 0;
	        for (Field field : fields) {
	            if (i != 0) {
	                buff.append(",");
	            }
	            buff.append(field.getName());
	            buff.append(":");
	            buff.append("\"");
	            buff.append(field.get(obj) == null ? "" : field.get(obj));
	            buff.append("\"");
	            i++;
	        }
	        buff.append("}");
	        buff.append("]");
	        json = buff.toString();
	    } catch (Exception e) {
	        throw new RuntimeException("cause:" + e.toString());
	    }
	    return json;
	}
	
	public static  String listToString(List ss) {
		StringBuffer s = new StringBuffer("");
		if (null != ss) {
			String[] str = new String[ss.size()];
			for (int i=0; i<ss.size(); i++){
				str[i] = ss.get(i).toString();
			}
			arrayToString(str);
			s.append(arrayToString(str));
		}
		return s.toString();
	}

 /**
	 * 把数组转换成'',格式的字符串输出
	 * @param ss
	 * @return
	 */
    public static String arrayToString(String[] ss){
		StringBuffer s = new StringBuffer("");
    	if(null != ss){
			for(int i=0;i<ss.length-1;i++){
				s.append("'")
				 .append(ss[i])
				 .append("'")
				 .append(",");
			}
			if(ss.length>0){
				s.append("'").append(ss[ss.length-1]).append("'");
			}
    	}
		return s.toString();
	}
	/**
	 *  Convert an array of strings to one string.
	 *  Put the 'separator' string between each element.
	 * @param a
	 * @param separator
	 * @return
	 */
	public static String arrayToString(String[] a, String separator) {
	    StringBuffer result = new StringBuffer();
	    if(a==null){
	    	return "";
	    }
	    if (a.length > 0) {
	        result.append(a[0]);
	        for (int i=1; i<a.length; i++) {
	            result.append(separator);
	            result.append(a[i]);
	        }
	    }
	    return result.toString();
	}
	
}