Java代码
public class JsonTool {

/**
* json字符串的格式化
*
* @param json
* @param fillStringUnit
* @return
*/
public static String formatJson(String json, String fillStringUnit) {
if (json == null || json.trim().length() == 0) {
return null;
}

int fixedLenth = 0;
ArrayList tokenList = new ArrayList();
{
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();
}

private 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);