JsonUtil

package com.huawei.cloud.util.cover;

import java.beans.IntrospectionException;
import java.beans.Introspector;
import java.beans.PropertyDescriptor;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.apache.log4j.Logger;


public class JsonUtil {

@SuppressWarnings("unused")
private static Logger log = Logger.getLogger(JsonUtil.class);


public static String objectTojson(Object obj) {
StringBuilder json = new StringBuilder();
if (obj == null) {
json.append("\"\"");
} else if (obj instanceof String ||
obj instanceof Integer ||
obj instanceof Float ||
obj instanceof Boolean ||
obj instanceof Short ||
obj instanceof Double ||
obj instanceof Long ||
obj instanceof BigDecimal ||
obj instanceof BigInteger ||
obj instanceof Byte) {
json.append("\"").append(stringTojson(obj.toString())).append("\"");
} else if (obj instanceof Object[]) {
json.append(arrayTojson((Object[]) obj));
} else if (obj instanceof List<?>) {
json.append(listTojson((List<?>) obj));
} else if (obj instanceof Map<?, ?>) {
json.append(mapTojson((Map<?, ?>) obj));
} else if (obj instanceof Set<?>) {
json.append(setTojson((Set<?>) obj));
} else {
json.append(beanTojson(obj));
}
return json.toString();
}


public static String beanTojson(Object bean) {
StringBuilder json = new StringBuilder();
json.append("{");
PropertyDescriptor[] props = null;
try {
props = Introspector.getBeanInfo(bean.getClass(), Object.class).getPropertyDescriptors();
} catch (IntrospectionException e) {}
if (props != null) {
for (int i = 0; i < props.length; i++) {
try {
String name = objectTojson(props[i].getName());
String value = objectTojson(props[i].getReadMethod().invoke(bean));
json.append(name);
json.append(":");
json.append(value);
json.append(",");
} catch (Exception e) {}
}
json.setCharAt(json.length() - 1, '}');
} else {
json.append("}");
}
return json.toString();
}


public static String listTojson(List<?> list) {
StringBuilder json = new StringBuilder();
json.append("[");
if (list != null && list.size() > 0) {
for (Object obj : list) {
json.append(objectTojson(obj));
json.append(",");
}
json.setCharAt(json.length() - 1, ']');
} else {
json.append("]");
}
return json.toString();
}


public static String arrayTojson(Object[] array) {
StringBuilder json = new StringBuilder();
json.append("[");
if (array != null && array.length > 0) {
for (Object obj : array) {
json.append(objectTojson(obj));
json.append(",");
}
json.setCharAt(json.length() - 1, ']');
} else {
json.append("]");
}
return json.toString();
}


public static String mapTojson(Map<?, ?> map) {
StringBuilder json = new StringBuilder();
json.append("{");
if (map != null && map.size() > 0) {
for (Object key : map.keySet()) {
json.append(objectTojson(key));
json.append(":");
json.append(objectTojson(map.get(key)));
json.append(",");
}
json.setCharAt(json.length() - 1, '}');
} else {
json.append("}");
}
return json.toString();
}


public static String setTojson(Set<?> set) {
StringBuilder json = new StringBuilder();
json.append("[");
if (set != null && set.size() > 0) {
for (Object obj : set) {
json.append(objectTojson(obj));
json.append(",");
}
json.setCharAt(json.length() - 1, ']');
} else {
json.append("]");
}
return json.toString();
}


public static String stringTojson(String s) {
if (s == null)
return "";
StringBuilder sb = new StringBuilder();
for (int i = 0; i < s.length(); i++) {
char ch = s.charAt(i);
switch (ch) {
case '"':
sb.append("\\\"");
break;
case '\\':
sb.append("\\\\");
break;
case '\b':
sb.append("\\b");
break;
case '\f':
sb.append("\\f");
break;
case '\n':
sb.append("\\n");
break;
case '\r':
sb.append("\\r");
break;
case '\t':
sb.append("\\t");
break;
case '/':
sb.append("\\/");
break;
default:
if (ch >= '\u0000' && ch <= '\u001F') {
String ss = Integer.toHexString(ch);
sb.append("\\u");
for (int k = 0; k < 4 - ss.length(); k++) {
sb.append('0');
}
sb.append(ss.toUpperCase());
} else {
sb.append(ch);
}
}
}
return sb.toString();
}
}