EntityWrapper使用解析
1、项目中引入jar包，我这里使用Maven构建
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus</artifactId>
<version>仓库最高版本号</version>
</dependency>
<!--快照版本使用,正式版本无需添加此仓库-->
<repository>
<id>snapshots</id>
<url>https://oss.sonatype.org/content/repositories/snapshots/</url>
</repository>特别说明： Mybatis及Mybatis-Spring依赖请勿加入项目配置，以免引起版本冲突！！！Mybatis-Plus会自动帮你维护！
2、springboot项目中application.yml文件中加上
mybatisplus:
enabled: true
generic:
enabled: true
dialectType: mysql传统SSM项目，修改配置文件，将mybatis的sqlSessionFactory替换成mybatis-plus的即可,mybatis-plus只做了一些功能的扩展:
<bean id="sqlSessionFactory" class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean">
<property name="dataSource" ref="dataSource"/>
<!-- 自动扫描Mapping.xml文件 -->
<property name="mapperLocations" value="classpath:mybatis
package com.baomidou.mybatisplus.mapper;
import java.io.Serializable;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.atomic.AtomicInteger;
import com.baomidou.mybatisplus.enums.SqlLike;
import com.baomidou.mybatisplus.exceptions.MybatisPlusException;
import com.baomidou.mybatisplus.toolkit.ArrayUtils;
import com.baomidou.mybatisplus.toolkit.CollectionUtils;
import com.baomidou.mybatisplus.toolkit.MapUtils;
import com.baomidou.mybatisplus.toolkit.SqlUtils;
import com.baomidou.mybatisplus.toolkit.StringUtils;
@SuppressWarnings("serial")
public abstract class Wrapper<T> implements Serializable {
private static final String PLACE_HOLDER = "{%s}";
private static final String MYBATIS_PLUS_TOKEN = "#{%s.paramNameValuePairs.%s}";
private static final String MP_GENERAL_PARAMNAME = "MPGENVAL";
private static final String DEFAULT_PARAM_ALIAS = "ew";
protected String paramAlias = null;
protected String sqlSelect = null;
protected SqlPlus sql = new SqlPlus();
protected Boolean isWhere;
protected String AND_OR = "AND";
private Map<String, Object> paramNameValuePairs = new HashMap<>(4);
private AtomicInteger paramNameSeq = new AtomicInteger(0);
public T getEntity() {
return null;
}
public String getSqlSelect() {
if (StringUtils.isEmpty(sqlSelect)) {
return null;
}
return stripSqlInjection(sqlSelect);
}
public Wrapper<T> setSqlSelect(String sqlSelect) {
if (StringUtils.isNotEmpty(sqlSelect)) {
this.sqlSelect = sqlSelect;
}
return this;
}
public abstract String getSqlSegment();
public String toString() {
String sqlSegment = getSqlSegment();
if (StringUtils.isNotEmpty(sqlSegment)) {
sqlSegment = sqlSegment.replaceAll("#\\{" + getParamAlias() + ".paramNameValuePairs.MPGENVAL[0-9]+}", "\\?");
}
return sqlSegment;
}
public Wrapper<T> where(String sqlWhere, Object... params) {
sql.WHERE(formatSql(sqlWhere, params));
return this;
}
public Wrapper<T> eq(String column, Object params) {
sql.WHERE(formatSql(String.format("%s = {0}", column), params));
return this;
}
public Wrapper<T> ne(String column, Object params) {
sql.WHERE(formatSql(String.format("%s <> {0}", column), params));
return this;
}
@SuppressWarnings({"rawtypes", "unchecked"})
public Wrapper<T> allEq(Map<String, Object> params) {
if (MapUtils.isNotEmpty(params)) {
Iterator iterator = params.entrySet().iterator();
while (iterator.hasNext()) {
Map.Entry<String, Object> entry = (Map.Entry<String, Object>) iterator.next();
Object value = entry.getValue();
if (StringUtils.checkValNotNull(value)) {
sql.WHERE(formatSql(String.format("%s = {0}", entry.getKey()), entry.getValue()));
}
}
}
return this;
}
public Wrapper<T> gt(String column, Object params) {
sql.WHERE(formatSql(String.format("%s > {0}", column), params));
return this;
}
public Wrapper<T> ge(String column, Object params) {
sql.WHERE(formatSql(String.format("%s >= {0}", column), params));
return this;
}
public Wrapper<T> lt(String column, Object params) {
sql.WHERE(formatSql(String.format("%s < {0}", column), params));
return this;
}
public Wrapper<T> le(String column, Object params) {
sql.WHERE(formatSql(String.format("%s <= {0}", column), params));
return this;
}
public Wrapper<T> and(String sqlAnd, Object... params) {
sql.AND().WHERE(formatSql(sqlAnd, params));
return this;
}
public Wrapper<T> andNew(String sqlAnd, Object... params) {
sql.AND_NEW().WHERE(formatSql(sqlAnd, params));
return this;
}
public Wrapper<T> and() {
sql.AND_NEW();
return this;
}
public Wrapper<T> or() {
sql.OR_NEW();
return this;
}
public Wrapper<T> or(String sqlOr, Object... params) {
if (StringUtils.isEmpty(sql.toString())) {
AND_OR = "OR";
}
sql.OR().WHERE(formatSql(sqlOr, params));
return this;
}
public Wrapper<T> orNew(String sqlOr, Object... params) {
if (StringUtils.isEmpty(sql.toString())) {
AND_OR = "OR";
}
sql.OR_NEW().WHERE(formatSql(sqlOr, params));
return this;
}
public Wrapper<T> groupBy(String columns) {
sql.GROUP_BY(columns);
return this;
}
public Wrapper<T> having(String sqlHaving, Object... params) {
sql.HAVING(formatSql(sqlHaving, params));
return this;
}
public Wrapper<T> orderBy(String columns) {
sql.ORDER_BY(columns);
return this;
}
public Wrapper<T> orderBy(String columns, boolean isAsc) {
if (StringUtils.isNotEmpty(columns)) {
sql.ORDER_BY(columns + (isAsc ? " ASC" : " DESC"));
}
return this;
}
public Wrapper<T> like(String column, String value) {
handerLike(column, value, SqlLike.DEFAULT, false);
return this;
}
public Wrapper<T> notLike(String column, String value) {
handerLike(column, value, SqlLike.DEFAULT, true);
return this;
}
private void handerLike(String column, String value, SqlLike type, boolean isNot) {
if (StringUtils.isNotEmpty(column) && StringUtils.isNotEmpty(value)) {
StringBuilder inSql = new StringBuilder();
inSql.append(column);
if (isNot) {
inSql.append(" NOT");
}
inSql.append(" LIKE {0}");
sql.WHERE(formatSql(inSql.toString(), SqlUtils.concatLike(value, type)));
}
}
public Wrapper<T> like(String column, String value, SqlLike type) {
handerLike(column, value, type, false);
return this;
}
public Wrapper<T> notLike(String column, String value, SqlLike type) {
handerLike(column, value, type, true);
return this;
}
public Wrapper<T> isNotNull(String columns) {
sql.IS_NOT_NULL(columns);
return this;
}
public Wrapper<T> isNull(String columns) {
sql.IS_NULL(columns);
return this;
}
public Wrapper<T> exists(String value) {
sql.EXISTS(value);
return this;
}
public Wrapper<T> notExists(String value) {
sql.NOT_EXISTS(value);
return this;
}
public Wrapper<T> in(String column, String value) {
if (StringUtils.isNotEmpty(value)) {
in(column, StringUtils.splitWorker(value, ",", -1, false));
}
return this;
}
public Wrapper<T> notIn(String column, String value) {
if (StringUtils.isNotEmpty(value)) {
notIn(column, StringUtils.splitWorker(value, ",", -1, false));
}
return this;
}
public Wrapper<T> in(String column, Collection<?> value) {
if (CollectionUtils.isNotEmpty(value))
sql.WHERE(formatSql(inExpression(column, value, false), value.toArray()));
return this;
}
public Wrapper<T> notIn(String column, Collection<?> value) {
if (CollectionUtils.isNotEmpty(value))
sql.WHERE(formatSql(inExpression(column, value, true), value.toArray()));
return this;
}
public Wrapper<T> in(String column, Object[] value) {
if (ArrayUtils.isNotEmpty(value))
sql.WHERE(formatSql(inExpression(column, Arrays.asList(value), false), value));
return this;
}
public Wrapper<T> notIn(String column, Object... value) {
if (ArrayUtils.isNotEmpty(value))
sql.WHERE(formatSql(inExpression(column, Arrays.asList(value), true), value));
return this;
}
private String inExpression(String column, Collection<?> value, boolean isNot) {
if (StringUtils.isNotEmpty(column) && CollectionUtils.isNotEmpty(value)) {
StringBuilder inSql = new StringBuilder();
inSql.append(column);
if (isNot) {
inSql.append(" NOT");
}
inSql.append(" IN ");
inSql.append("(");
int size = value.size();
for (int i = 0; i < size; i++) {
inSql.append(String.format(PLACE_HOLDER, i));
if (i + 1 < size) {
inSql.append(",");
}
}
inSql.append(")");
return inSql.toString();
}
return null;
}
public Wrapper<T> between(String column, Object val1, Object val2) {
sql.WHERE(formatSql(String.format("%s BETWEEN {0} AND {1}", column), val1, val2));
return this;
}
public Wrapper<T> notBetween(String column, Object val1, Object val2) {
sql.WHERE(formatSql(String.format("%s NOT BETWEEN {0} AND {1}", column), val1, val2));
return this;
}
public Wrapper<T> addFilter(String sqlWhere, Object... params) {
return and(sqlWhere, params);
}
public Wrapper<T> addFilterIfNeed(boolean need, String sqlWhere, Object... params) {
return need ? where(sqlWhere, params) : this;
}
protected String stripSqlInjection(String value) {
return value.replaceAll("('.+--)|(--)|(\\|)|(%7C)", "");
}
protected String formatSql(String sqlStr, Object... params) {
return formatSqlIfNeed(true, sqlStr, params);
}
protected String formatSqlIfNeed(boolean need, String sqlStr, Object... params) {
if (!need || StringUtils.isEmpty(sqlStr)) {
return null;
}
// #200
if (ArrayUtils.isNotEmpty(params)) {
for (int i = 0; i < params.length; ++i) {
String genParamName = MP_GENERAL_PARAMNAME + paramNameSeq.incrementAndGet();
sqlStr = sqlStr.replace(String.format(PLACE_HOLDER, i),
String.format(MYBATIS_PLUS_TOKEN, getParamAlias(), genParamName));
paramNameValuePairs.put(genParamName, params[i]);
}
}
return sqlStr;
}
public Wrapper<T> isWhere(Boolean bool) {
this.isWhere = bool;
return this;
}
public Wrapper<T> limit(int begin, int end) {
sql.LIMIT(begin, end);
return this;
}
public Map<String, Object> getParamNameValuePairs() {
return paramNameValuePairs;
}
public String getParamAlias() {
return StringUtils.isEmpty(paramAlias) ? DEFAULT_PARAM_ALIAS : paramAlias;
}
public Wrapper<T> setParamAlias(String paramAlias) {
if (StringUtils.isNotEmpty(getSqlSegment())) {
throw new MybatisPlusException("Error: Please call this method when initializing!");
}
if (StringUtils.isNotEmpty(this.paramAlias)) {
throw new MybatisPlusException("Error: Please do not call the method repeatedly!");
}
this.paramAlias = paramAlias;
return this;
}
}最后说一句，阅读源码，你会收获很多，看到别人的处理方式，你会有很大进步的。哈哈，今天你学到了吗
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程网。
