1 package gemu.test.json;
 2
 3 import java.io.File;
 4 import java.io.FileWriter;
 5 import java.io.IOException;
 6 import java.io.Writer;
 7
 8 import net.sf.json.JSONArray;
 9
10 public class WritePrettyJSON {
11
12     public static void main(String[] args) throws IOException {
13
14         File file = new File("D:/json.json");
15         String jsonStr = "[{a:1,b:{b1:[{a:2},{a:1}]},c:3},{a:1},{b:1}]";
16 //        String jsonStr = "{a:1,b:{b1:[{a:2},{a:1}]},c:3,a:2,b:2}";
17         JSONArray jsonObj = JSONArray.fromObject(jsonStr);
18 //        JSONObject jsonObj = JSONObject.fromObject(jsonStr);
19
20         char[] stack = new char[1024]; // 存放括号，如 "{","}","[","]"
21         int top = -1;
22
23         String string = jsonObj.toString();
24         StringBuffer sb = new StringBuffer();
25         char[] charArray = string.toCharArray();
26         for (int i = 0; i < charArray.length; i++) {
27             char c = charArray[i];
28             if ('{' == c || '[' == c) {
29                 stack[++top] = c; // 将括号添加到数组中，这个可以简单理解为栈的入栈
30                 sb.append(charArray[i] + "\n");
31                 for (int j = 0; j <= top; j++) {
32                     sb.append("\t");
33                 }
34                 continue;
35             }
36             if ((i + 1) <= (charArray.length - 1)) {
37                 char d = charArray[i+1];
38                 if ('}' == d || ']' == d) {
39                     top--; // 将数组的最后一个有效内容位置下标减 1，可以简单的理解为将栈顶数据弹出
40                     sb.append(charArray[i] + "\n");
41                     for (int j = 0; j <= top; j++) {
42                         sb.append("\t");
43                     }
44                     continue;
45                 }
46             }
47             if (',' == c) {
48                 sb.append(charArray[i] + "\n");
49                 for (int j = 0; j <= top; j++) {
50                     sb.append("\t");
51                 }
52                 continue;
53             }
54             sb.append(c);
55         }
56
57         Writer write = new FileWriter(file);
58         write.write(sb.toString());
59         write.flush();
60         write.close();
61     }
62 }