Mybatis的批量插入确实很好用，但是当数据量特别大的时候可能一次批量插入2000条数据就死翘翘了。怎么办呢？当然是原生sql是最快的啦，10000条数据秒入无压力。下面是将对象集合拼接成批量插入MySQL的简单工具
package com.qing;
import org.apache.commons.lang3.StringUtils;
import org.springframework.util.CollectionUtils;
import java.lang.reflect.Field;
import java.util.List;
public class SqlJointUtils {
private static final String UNDERLINE = "_";
private static final String SINGLE_QUOTES = "'";
private static final String COMMA = ",";
private static final String LEFT_BRACKET = "(";
private static final String RIGHT_BRACKET = ")";
private static final String BACKQUOTE = "`";
/**
* * 批量插入
* *
* * @param list 对象集合
* * @param tableName 表名
* * @param
* * @return java.lang.String
*
*/
public static
if (CollectionUtils.isEmpty(list)) {
return null;
}
T t = list.get(0);
String jointSqlColumnName = jointSqlColumnName(t.getClass(), tableName);
StringBuilder sb = new StringBuilder(jointSqlColumnName);
for (T value : list) {
sb.append(LEFT_BRACKET);
Class aClass = value.getClass();
Field[] fields = aClass.getDeclaredFields();
for (Field field : fields) {
try {
if ("id".equals(field.getName())) {
continue;
}
field.setAccessible(true);
Object o = field.get(value);
String name = field.getType().getSimpleName();
switch (name) {
case "String":
String s = (String) o;
if (StringUtils.isBlank(s)) {
sb.append((String) null).append(COMMA);
} else {
sb.append(SINGLE_QUOTES).append(s).append(SINGLE_QUOTES).append(COMMA);
}
break;
case "Integer":
Integer integer = (Integer) o;
if (integer == null) {
sb.append((String) null).append(COMMA);
} else {
sb.append(integer).append(COMMA);
}
break;
case "Date":
sb.append("now(),");
break;
case "Long":
Long l = (Long) o;
if (l == null) {
sb.append((String) null).append(COMMA);
} else {
sb.append(l).append(COMMA);
}
default:
}
} catch (IllegalAccessException e) {
e.printStackTrace();
}
}
sb.replace(sb.length() - 1, sb.length() - 1, RIGHT_BRACKET);
}
//去掉会后一个“,”
return sb.substring(0, sb.length() - 1);
}
/**
* * 拼接sql插入字段名
* *
* * @param c 实体类类型
* * @param tableName 表名
* * @return java.lang.String
*
*/
public static String jointSqlColumnName(Class c, String tableName) {
StringBuilder sb = new StringBuilder();
sb.append("insert into ").append(BACKQUOTE).append(tableName).append(BACKQUOTE).append(LEFT_BRACKET);
Field[] fields = c.getDeclaredFields();
for (Field field : fields) {
String name = field.getName();
if ("id".equals(name)) {
continue;
}
String s = fieldConvertColumn(name);
sb.append(BACKQUOTE).append(s).append(BACKQUOTE).append(COMMA);
}
return sb.substring(0, sb.length() - 1) + ") values";
}
/**
* * java对象属性名转数据库字段名
* *
* * @param s 属性名
* * @return java.lang.String
*
*/
static String fieldConvertColumn(String s) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < s.length(); i++) {
char c = s.charAt(i);
if (Character.isUpperCase(c)) {
sb.append(UNDERLINE);
}
sb.append(c);
}
return sb.toString().toLowerCase();
}
}
目前只对字符串类型、时间和整型类型做了处理，后续将优化。
主键未处理，后续将优化