JsonFormatTool.java

package com.BeeFramework.Utils;

import java.util.ArrayList;

public class JsonFormatTool {

	/**
     * json字符串的格式化
     * @author peiyuxin
     * @param json 需要格式的json串
     * @param fillStringUnit每一层之前的占位符号比如空格 制表符
     * @return
     */
    public static String formatJson(String json, String fillStringUnit) {
        if (json == null || json.trim().length() == 0) {
            return null;
        }
         
        int fixedLenth = 0;
        ArrayList<String> tokenList = new ArrayList<String>();
        {
            String jsonTemp = json;
            //预读取
            while (jsonTemp.length() > 0) {
                String token = getToken(jsonTemp);
                jsonTemp = jsonTemp.substring(token.length());
                token = token.trim();
                tokenList.add(token);
            }            
        }
         
        for (int i = 0; i < tokenList.size(); i++) {
            String token = tokenList.get(i);
            int length = token.getBytes().length;
            if (length > fixedLenth && i < tokenList.size() - 1 && tokenList.get(i + 1).equals(":")) {
                fixedLenth = length;
            }
        }
         
        StringBuilder buf = new StringBuilder();
        int count = 0;
        for (int i = 0; i < tokenList.size(); i++) {
             
            String token = tokenList.get(i);
             
            if (token.equals(",")) {
                buf.append(token);
                doFill(buf, count, fillStringUnit);
                continue;
            }
            if (token.equals(":")) {
                buf.append("").append(token).append(" ");
                continue;
            }
            if (token.equals("{")) {
                String nextToken = tokenList.get(i + 1);
                if (nextToken.equals("}")) {
                    i++;
                    buf.append("{ }");
                } else {
                    count++;
                    buf.append(token);
                    doFill(buf, count, fillStringUnit);
                }
                continue;
            }
            if (token.equals("}")) {
                count--;
                doFill(buf, count, fillStringUnit);
                buf.append(token);
                continue;
            }
            if (token.equals("[")) {
                String nextToken = tokenList.get(i + 1);
                if (nextToken.equals("]")) {
                    i++;
                    buf.append("[ ]");
                } else {
                    count++;
                    buf.append(token);
                    doFill(buf, count, fillStringUnit);
                }
                continue;
            }
            if (token.equals("]")) {
                count--;
                doFill(buf, count, fillStringUnit);
                buf.append(token);
                continue;
            }
             
            buf.append(token);
            //左对齐
            if (i < tokenList.size() - 1 && tokenList.get(i + 1).equals(":")) {
                int fillLength = fixedLenth - token.getBytes().length;
                if (fillLength > 0) {
                    for(int j = 0; j < fillLength; j++) {
                        buf.append("");
                    }
                }
            }
        }
        return buf.toString();
    }
     
    public static String getToken(String json) {
        StringBuilder buf = new StringBuilder();
        boolean isInYinHao = false;
        while (json.length() > 0) {
            String token = json.substring(0, 1);
            json = json.substring(1);
             
            if (!isInYinHao &&  
                    (token.equals(":") || token.equals("{") || token.equals("}")  
                            || token.equals("[") || token.equals("]")
                            || token.equals(","))) {
                if (buf.toString().trim().length() == 0) {                   
                    buf.append(token);
                }
                 
                break;
            }
 
            if (token.equals("\\")) {
                buf.append(token);
                buf.append(json.substring(0, 1));
                json = json.substring(1);
                continue;
            }
            if (token.equals("\"")) {
                buf.append(token);
                if (isInYinHao) {
                    break;
                } else {
                    isInYinHao = true;
                    continue;
                }                
            }
            buf.append(token);
        }
        return buf.toString();
    }
 
    private static void doFill(StringBuilder buf, int count, String fillStringUnit) {
        buf.append("\n");
        for (int i = 0; i < count; i++) {
            buf.append(fillStringUnit);
        }
    }
  
}