init

src/main/java/com/newyetai/mybatisplus/config/AutoMetaObjectHandler.java

@@ -0,0 +1,26 @@
+package com.newyetai.mybatisplus.config;
+
+import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
+import com.newyetai.common.util.UserContextHolder;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.ibatis.reflection.MetaObject;
+import org.springframework.stereotype.Component;
+
+import java.util.Date;
+
+@Slf4j
+//@Component
+public class AutoMetaObjectHandler implements MetaObjectHandler {
+  @Override
+  public void insertFill(MetaObject metaObject) {
+    this.strictInsertFill(metaObject, "deleted", Boolean.class, Boolean.FALSE);
+    this.strictInsertFill(metaObject, "createTime", Date.class, new Date());
+    this.strictInsertFill(metaObject, "createBy", Long.class, UserContextHolder.getLoginUserId());
+  }
+
+  @Override
+  public void updateFill(MetaObject metaObject) {
+    this.strictUpdateFill(metaObject, "updateBy", Long.class, UserContextHolder.getLoginUserId());
+    this.strictUpdateFill(metaObject, "updateTime", Date.class, new Date());
+  }
+}

src/main/java/com/newyetai/mybatisplus/config/MybatisPlusConfig.java

@@ -0,0 +1,24 @@
+package com.newyetai.mybatisplus.config;
+
+import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
+import com.baomidou.mybatisplus.extension.plugins.pagination.optimize.JsqlParserCountOptimize;
+import org.mybatis.spring.annotation.MapperScan;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@MapperScan(basePackages = {"com.newyetai.**.dao.**"})
+public class MybatisPlusConfig {
+
+  @Bean
+  public PaginationInterceptor paginationInterceptor() {
+    PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
+    // 设置请求的页面大于最大页后操作， true调回到首页，false 继续请求  默认false
+    // paginationInterceptor.setOverflow(false);
+    // 设置最大单页限制数量，默认 500 条，-1 不受限制
+    // paginationInterceptor.setLimit(500);
+    // 开启 count 的 join 优化,只针对部分 left join
+    paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
+    return paginationInterceptor;
+  }
+}

src/main/java/com/newyetai/mybatisplus/injector/Exists.java

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+package com.newyetai.mybatisplus.injector;
+
+import org.apache.ibatis.mapping.MappedStatement;
+import org.apache.ibatis.mapping.SqlSource;
+
+import com.baomidou.mybatisplus.core.enums.SqlMethod;
+import com.baomidou.mybatisplus.core.injector.AbstractMethod;
+import com.baomidou.mybatisplus.core.metadata.TableInfo;
+import com.baomidou.mybatisplus.core.toolkit.sql.SqlScriptUtils;
+
+public class Exists extends AbstractMethod {
+
+  @Override
+  public MappedStatement injectMappedStatement(Class<?> mapperClass, Class<?> modelClass,
+      TableInfo tableInfo) {
+    SqlMethod sqlMethod = SqlMethod.SELECT_COUNT;
+    String sql =
+        String.format("<script> SELECT CASE WHEN COUNT(1) > 0 THEN 1 ELSE 0 end  FROM %s %s \n</script>", tableInfo.getTableName(),
+            sqlWhereEntity(true, tableInfo));
+    SqlSource sqlSource = languageDriver.createSqlSource(configuration, sql, modelClass);
+    return this.addSelectMappedStatementForOther(mapperClass, getMethod(sqlMethod), sqlSource, Boolean.class);
+  }
+
+  protected String sqlWhereEntity(boolean newLine, TableInfo table) {
+    
+    String sqlScript = table.getAllSqlWhere(false, false, ENTITY_DOT);
+    
+    String newKeyProperty = ENTITY_DOT + table.getKeyProperty();
+    String keySqlScript =
+        table.getKeyColumn() + HTML_LT + HTML_GT + SqlScriptUtils.safeParam(newKeyProperty);
+    sqlScript =
+        SqlScriptUtils.convertIf(keySqlScript, String.format("%s != null", newKeyProperty), false)
+            + NEWLINE + sqlScript;
+    
+    sqlScript = SqlScriptUtils.convertIf(sqlScript, String.format("%s != null", ENTITY), true);
+    sqlScript = SqlScriptUtils.convertWhere(sqlScript) + NEWLINE;
+    return newLine ? NEWLINE + sqlScript : sqlScript;
+  }
+
+  @Override
+  public String getMethod(SqlMethod sqlMethod) {
+    // 自定义 mapper 方法名
+    return "existsEntity";
+  }
+
+}

src/main/java/com/newyetai/mybatisplus/injector/MySqlInjector.java

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+package com.newyetai.mybatisplus.injector;
+
+import java.util.List;
+
+import org.springframework.stereotype.Component;
+
+import com.baomidou.mybatisplus.annotation.FieldFill;
+import com.baomidou.mybatisplus.core.injector.AbstractMethod;
+import com.baomidou.mybatisplus.core.injector.DefaultSqlInjector;
+import com.baomidou.mybatisplus.extension.injector.methods.AlwaysUpdateSomeColumnById;
+
+@Component
+public class MySqlInjector extends DefaultSqlInjector {
+  @Override
+  public List<AbstractMethod> getMethodList(Class<?> mapperClass) {
+      List<AbstractMethod> methodList = super.getMethodList(mapperClass);
+      /**
+       * 把两个扩展内置扩展SQL注入器注入
+       */
+//      methodList.add(new InsertBatchSomeColumn(i -> i.getFieldFill() != FieldFill.UPDATE));
+      methodList.add(new AlwaysUpdateSomeColumnById(i -> i.getFieldFill() != FieldFill.INSERT));
+      methodList.add(new Exists());
+      return methodList;
+  }
+}

src/main/java/com/newyetai/mybatisplus/util/MybatisPlusUtils.java

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+package com.newyetai.mybatisplus.util;
+
+import java.lang.reflect.Field;
+import java.util.Arrays;
+
+import com.baomidou.mybatisplus.annotation.EnumValue;
+
+public class MybatisPlusUtils {
+  
+  /**
+   * 处理枚举字段
+   * @param obj
+   * @return
+   * @throws IllegalArgumentException
+   * @throws IllegalAccessException
+   * @author sr on 2022-02-21 
+   */
+  public static Object dealEnumField(Object obj) throws IllegalArgumentException, IllegalAccessException {
+    if (obj == null) {
+      return null;
+    }
+    Class<?> clazz = obj.getClass();
+    if (!clazz.isEnum()) {
+      return obj;
+    }
+    Field f = Arrays.stream(clazz.getDeclaredFields())
+        .filter(field -> field.isAnnotationPresent(EnumValue.class)).findFirst().get();
+    f.setAccessible(true);
+    return f.get(obj);
+  }
+  
+
+}