用Java对JSON字符串进行格式化输出

工作中进行http相关接口测试时经常会收到返回的json数据，因为没有格式化输入到控制台后看起来很不直观。

早上写了一个小工具类，对这JSON串进行格式化输出，代替System.out.print

package MyTest;
/**
 * 格式化输入工具类
 * @author lizhgb
 * @date  2015-10-14
 *
 */
public final class FormatUtil {

	/**
	 * 打印输入到控制台
	 * @param jsonStr
	 * @author   lizhgb
	 * @Date   2015-10-14 下午1:17:22
	 */
	public static void printJson(String jsonStr){
		System.out.println(formatJson(jsonStr));
	}

	/**
	 * 格式化
	 * @param jsonStr
	 * @return
	 * @author   lizhgb
	 * @Date   2015-10-14 下午1:17:35
	 */
    public static String formatJson(String jsonStr) {
        if (null == jsonStr || "".equals(jsonStr)) return "";
        StringBuilder sb = new StringBuilder();
        char last = ‘\0‘;
        char current = ‘\0‘;
        int indent = 0;
        for (int i = 0; i < jsonStr.length(); i++) {
            last = current;
            current = jsonStr.charAt(i);
            switch (current) {
                case ‘{‘:
                case ‘[‘:
                    sb.append(current);
                    sb.append(‘\n‘);
                    indent++;
                    addIndentBlank(sb, indent);
                    break;
                case ‘}‘:
                case ‘]‘:
                    sb.append(‘\n‘);
                    indent--;
                    addIndentBlank(sb, indent);
                    sb.append(current);
                    break;
                case ‘,‘:
                    sb.append(current);
                    if (last != ‘\\‘) {
                        sb.append(‘\n‘);
                        addIndentBlank(sb, indent);
                    }
                    break;
                default:
                    sb.append(current);
            }
        }

        return sb.toString();
    }

    /**
     * 添加space
     * @param sb
     * @param indent
     * @author   lizhgb
     * @Date   2015-10-14 上午10:38:04
     */
    private static void addIndentBlank(StringBuilder sb, int indent) {
        for (int i = 0; i < indent; i++) {
            sb.append(‘\t‘);
        }
    }
}

测试：

@Test
	public void jsonPrintTest2() {

		String str = "{\"content\":\"this is the msg content.\",\"tousers\":\"user1|user2\",\"msgtype\":\"texturl\",\"appkey\":\"test\",\"domain\":\"test\","
				+ "\"system\":{\"wechat\":{\"safe\":\"1\"}},\"texturl\":{\"urltype\":\"0\",\"user1\":{\"spStatus\":\"user01\",\"workid\":\"work01\"},\"user2\":{\"spStatus\":\"user02\",\"workid\":\"work02\"}}}";
		FormatUtil.printJson(str);
	}

输出：

{
	"content":"this is the msg content.",
	"tousers":"user1|user2",
	"msgtype":"texturl",
	"appkey":"test",
	"domain":"test",
	"system":{
		"wechat":{
			"safe":"1"
		}
	},
	"texturl":{
		"urltype":"0",
		"user1":{
			"spStatus":"user01",
			"workid":"work01"
		},
		"user2":{
			"spStatus":"user02",
			"workid":"work02"
		}
	}
}