java List、Object、String

import java.math.BigInteger;

import java.util.List;

import java.util.Map;

import java.util.Set;

import org.apache.commons.logging.Log;

import org.apache.commons.logging.LogFactory;

public class JsonUtil {

private static Log log = LogFactory.getLog(JsonUtil.class);

public static String object2json(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(string2json(obj.toString())).append(""");

} else if (obj instanceof Object[]) {

json.append(array2json((Object[]) obj));

} else if (obj instanceof List) {

json.append(list2json((List<?>) obj));

} else if (obj instanceof Map) {

json.append(map2json((Map<?, ?>) obj));

} else if (obj instanceof Set) {

json.append(set2json((Set<?>) obj));

} else {

json.append(bean2json(obj));

}

return json.toString();

}

public static String bean2json(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 = object2json(props[i].getN 《一线大厂 Java 面试题解析+后端开发学习笔记+最新架构讲解视频+实战项目源码讲义》无偿开源 威信搜索公众号【编程进阶路】 ame());

String value = object2json(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 list2json(List<?> list) {

StringBuilder json = new StringBuilder();

json.append("[");

if (list != null && list.size() > 0) {

for (Object obj : list) {

json.append(object2json(obj));

json.append(",");

}

json.setCharAt(json.length() - 1, ']');

} else {

json.append("]");

}

return json.toString();

}

public static String array2json(Object[] array) {

StringBuilder json = new StringBuilder();

json.append("[");

if (array != null && array.length > 0) {

for (Object obj : array) {

json.append(object2json(obj));

json.append(",");

}

json.setCharAt(json.length() - 1, ']');

} else {

json.append("]");

}

return json.toString();

}

public static String map2json(Map<?, ?> map) {

StringBuilder json = new StringBuilder();

json.append("{");

if (map != null && map.size() > 0) {

for (Object key : map.keySet()) {

json.append(object2json(key));

json.append(":");

json.append(object2json(map.get(key)));

json.append(",");

}

json.setCharAt(json.length() - 1, '}');

} else {

json.append("}");

}

return json.toString();

}

public static String set2json(Set<?> set) {