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| package com.lt.yl.mine.utils;
import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
public class R {
public static <T, R> String c(SFunction<T, R> fn) {
return LambdaUtils.columnToString(fn);
}
}
------------------------------------
package com.lt.yl.mine.utils;
import com.baomidou.mybatisplus.core.toolkit.support.SFunction;
import com.lt.yl.mine.exception.ProjectException;
import java.io.Serializable;
import java.lang.invoke.SerializedLambda;
import java.lang.reflect.Method;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
public class LambdaUtils {
private static Map<Class, SerializedLambda> CLASS_LAMBDA_CACHE = new ConcurrentHashMap<>();
private static String GET_METHOD_PREFIX = "get";
private static String SET_METHOD_PREFIX = "set";
public static <T, R> String columnToString(SFunction<T, R> fn) {
SerializedLambda lambda = getSerializedLambda(fn);
String methodName = lambda.getImplMethodName();
if (methodName.startsWith(GET_METHOD_PREFIX) || methodName.startsWith(SET_METHOD_PREFIX)) {
return ConverterUtils.camelToUnderline(methodName.substring(3));
} else {
throw new ProjectException("please income a getter/setter method");
}
}
private static SerializedLambda getSerializedLambda(Serializable fn) {
SerializedLambda lambda = CLASS_LAMBDA_CACHE.get(fn.getClass());
if(lambda == null) {
try {
Method method = fn.getClass().getDeclaredMethod("writeReplace");
method.setAccessible(Boolean.TRUE);
lambda = (SerializedLambda) method.invoke(fn);
CLASS_LAMBDA_CACHE.put(fn.getClass(), lambda);
} catch (Exception e) {
throw new ProjectException("get {} SerializedLambda error", fn.getClass());
}
}
return lambda;
}
}
-------------------------------------
package com.lt.yl.mine.utils;
import org.apache.commons.lang3.StringUtils;
import java.text.DecimalFormat;
import java.util.*;
public class ConverterUtils {
public static String camelToUnderline(String param){
if (param == null || "".equals(param.trim())) {
return "";
}
int len = param.length();
StringBuilder sb = new StringBuilder(len);
for (int i = 0; i < len; i++) {
char c = param.charAt(i);
if(i == 0 && Character.isUpperCase(c)){
sb.append(Character.toLowerCase(c));
}else if(Character.isUpperCase(c) && i != 0) {
sb.append("_");
sb.append(Character.toLowerCase(c));
} else {
sb.append(c);
}
}
return sb.toString();
}
public static String underlineToCamel(String param) {
if (param == null || "".equals(param.trim())) {
return "";
}
int len = param.length();
StringBuilder sb = new StringBuilder(len);
for (int i = 0; i < len; i++) {
char c = param.charAt(i);
if(i == 0){
sb.append(Character.toLowerCase(param.charAt(i)));
}else if (c == '_') {
if (++i < len) {
sb.append(Character.toUpperCase(param.charAt(i)));
}
} else {
sb.append(c);
}
}
return sb.toString();
}
public static Map<String ,Object> underlineToCamel(Map<String, Object> map) {
if (map == null || map.isEmpty()) {
return map;
}
Map<String ,Object> resultMap = new HashMap<>();
map.forEach((k, v) -> {
resultMap.put(underlineToCamel(k), v);
});
return resultMap;
}
public static List<Map<String ,Object>> underlineToCamel(List<Map<String, Object>> mapList) {
if (mapList == null || mapList.isEmpty()) {
return mapList;
}
List<Map<String ,Object>> resultMapList = new ArrayList<>(mapList.size());
Map<String, String> mapHandler = new HashMap<>();
Map<String, Object> firstMap = mapList.get(0);
Map<String, Object> mappingFirstMap = new HashMap<>();
firstMap.forEach((k, v) -> {
String camel = underlineToCamel(k);
mappingFirstMap.put(camel, v);
mapHandler.put(k, camel);
});
resultMapList.add(mappingFirstMap);
for (int i = 1; i < mapList.size(); i++) {
Map<String ,Object> resultMap = new HashMap<>();
mapList.get(i).forEach((k, v) -> {
resultMap.put(mapHandler.get(k), v);
});
resultMapList.add(resultMap);
}
return resultMapList;
}
public static String parseDouble2Decimal(Object value){
if(value == null || StringUtils.isBlank(value.toString())){
return "0";
}
double a = Double.parseDouble(value.toString());
if (a == 0) {
return "0";
}
return new DecimalFormat("0.00").format(value);
}
public static Double parseDouble(String s) {
if (StringUtils.isNotBlank(s)) {
return Double.parseDouble(s);
}
return null;
}
public static String parseString(Object obj) {
if (obj != null && StringUtils.isNotBlank(obj.toString())) {
return obj.toString();
}
return null;
}
public static String toUpperCaseFirstOne(String s) {
if(Character.isUpperCase(s.charAt(0)))
return s;
else
return Character.toUpperCase(s.charAt(0)) + s.substring(1);
}
public static void main(String[] args) {
Map<String ,Object> map = new HashMap<>();
map.put("test_date", 21);
map.put("test_string", 21);
underlineToCamel(map).keySet().forEach(System.out::println);
}
}
|
