增加分页插件limit参数配置.

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/toolkit/ClassUtils.java

@@ -119,6 +119,20 @@ public final class ClassUtils {
             throw ExceptionUtils.mpe("实例化对象时出现错误,请尝试给 %s 添加无参的构造方法", e, clazz.getName());
         }
     }
+    
+    /**
+     * 实例化对象.
+     *
+     * @param clazzName 类名
+     * @param <T>       类型
+     * @return 实例
+     * @since 3.3.2
+     */
+    @SuppressWarnings("unchecked")
+    public static <T> T newInstance(String clazzName) {
+        return (T) newInstance(toClassConfident(clazzName));
+    }
+    
 
     /**
      * <p>

mybatis-plus-extension/src/main/java/com/baomidou/mybatisplus/extension/plugins/PaginationInterceptor.java

@@ -274,37 +274,25 @@ public class PaginationInterceptor extends AbstractSqlParserHandler implements I
     @Override
     public void setProperties(Properties prop) {
         String countSqlParser = prop.getProperty("countSqlParser");
-        if (StringUtils.isNotBlank(countSqlParser)) {
-            setSqlParser(countSqlParser);
-        }
         String overflow = prop.getProperty("overflow");
-        setOverflow(Boolean.parseBoolean(overflow));
+        String limit = prop.getProperty("limit");
         String dialectType = prop.getProperty("dialectType");
         String dialectClazz = prop.getProperty("dialectClazz");
+        setOverflow(Boolean.parseBoolean(overflow));
+        if (StringUtils.isNotBlank(countSqlParser)) {
+            setCountSqlParser(ClassUtils.newInstance(countSqlParser));
+        }
         if (StringUtils.isNotBlank(dialectType)) {
             setDialectType(dialectType);
         }
         if (StringUtils.isNotBlank(dialectClazz)) {
             setDialectClazz(dialectClazz);
         }
-    }
-
-    /**
-     * 根据配置文件设置 countSqlParser
-     * @param countSqlParser
-     */
-    public void setSqlParser(String countSqlParser) {
-        try {
-            Class<?> clazz = Class.forName(countSqlParser);
-            if (ISqlParser.class.isAssignableFrom(clazz)) {
-                ISqlParser sqlParser = ClassUtils.newInstance((Class<? extends ISqlParser>) clazz);
-                setCountSqlParser(sqlParser);
-            }
-        } catch (ClassNotFoundException e) {
-            throw ExceptionUtils.mpe("Class : %s is not found", countSqlParser);
+        if (StringUtils.isNotBlank(limit)) {
+            setLimit(Long.parseLong(limit));
         }
     }
-
+    
     /**
      * 设置方言类型
      *

mybatis-plus-extension/src/main/java/com/baomidou/mybatisplus/extension/plugins/pagination/DialectFactory.java

@@ -18,7 +18,6 @@ package com.baomidou.mybatisplus.extension.plugins.pagination;
 import com.baomidou.mybatisplus.annotation.DbType;
 import com.baomidou.mybatisplus.core.exceptions.MybatisPlusException;
 import com.baomidou.mybatisplus.core.metadata.IPage;
-import com.baomidou.mybatisplus.core.toolkit.Assert;
 import com.baomidou.mybatisplus.core.toolkit.ClassUtils;
 import com.baomidou.mybatisplus.core.toolkit.StringUtils;
 import com.baomidou.mybatisplus.extension.plugins.pagination.dialects.DialectRegistry;
@@ -72,7 +71,7 @@ public class DialectFactory {
     @Deprecated
     private static IDialect getDialect(DbType dbType, String dialectClazz) {
         //这里需要注意一下，就的版本是把dbType和dialectClazz同时传进来的，所以会存在dbType是一定会有值，dialectClazz可能为空的情况，兼容需要先判断dialectClazz
-        return StringUtils.isBlank(dialectClazz) ? DIALECT_REGISTRY.getDialect(dbType) : DIALECT_CACHE.computeIfAbsent(dialectClazz, DialectFactory::classToDialect);
+        return StringUtils.isBlank(dialectClazz) ? DIALECT_REGISTRY.getDialect(dbType) : DIALECT_CACHE.computeIfAbsent(dialectClazz, ClassUtils::newInstance);
     }
 
     /**
@@ -83,23 +82,12 @@ public class DialectFactory {
      * @since 3.3.1
      */
     public static IDialect getDialect(String dialectClazz) {
-        return DIALECT_CACHE.computeIfAbsent(dialectClazz, DialectFactory::classToDialect);
+        return DIALECT_CACHE.computeIfAbsent(dialectClazz, ClassUtils::newInstance);
     }
     
     public static IDialect getDialect(DbType dbType) {
         return Optional.ofNullable(DIALECT_REGISTRY.getDialect(dbType))
             .orElseThrow(() -> new MybatisPlusException(String.format("%s database not supported.", dbType.getDb())));
     }
-
-    @Deprecated
-    private static IDialect newInstance(Class<? extends IDialect> dialectClazz) {
-        IDialect dialect = ClassUtils.newInstance(dialectClazz);
-        Assert.notNull(dialect, "The value of the dialect property in mybatis configuration.xml is not defined.");
-        return dialect;
-    }
-
-    @SuppressWarnings("unchecked")
-    private static IDialect classToDialect(String dialectClazz) {
-        return ClassUtils.newInstance((Class<? extends IDialect>) ClassUtils.toClassConfident(dialectClazz));
-    }
+    
 }

mybatis-plus-extension/src/test/java/com/baomidou/mybatisplus/extension/plugins/pagination/PaginationInterceptorTest.java

@@ -0,0 +1,94 @@
+package com.baomidou.mybatisplus.extension.plugins.pagination;
+
+import com.baomidou.mybatisplus.annotation.DbType;
+import com.baomidou.mybatisplus.extension.parsers.BlockAttackSqlParser;
+import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
+import com.baomidou.mybatisplus.extension.plugins.pagination.dialects.DB2Dialect;
+import com.baomidou.mybatisplus.extension.plugins.pagination.dialects.MySqlDialect;
+import com.baomidou.mybatisplus.extension.plugins.tenant.TenantSqlParser;
+import org.apache.ibatis.reflection.MetaObject;
+import org.apache.ibatis.reflection.SystemMetaObject;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.util.Properties;
+
+
+/**
+ * @author nieqiurong 2020/4/10.
+ */
+@ExtendWith(MockitoExtension.class)
+class PaginationInterceptorTest {
+    
+    @Test
+    void testSetCountSqlParser() {
+        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
+        MetaObject metaObject = SystemMetaObject.forObject(paginationInterceptor);
+        Assertions.assertNull(metaObject.getValue("countSqlParser"));
+        Properties properties = new Properties();
+        properties.setProperty("countSqlParser", BlockAttackSqlParser.class.getName());
+        paginationInterceptor.setProperties(properties);
+        Assertions.assertEquals(metaObject.getValue("countSqlParser").getClass().getName(), BlockAttackSqlParser.class.getName());
+        paginationInterceptor.setCountSqlParser(new TenantSqlParser());
+        Assertions.assertEquals(metaObject.getValue("countSqlParser").getClass().getName(), TenantSqlParser.class.getName());
+    }
+    
+    @Test
+    void testSetOverflow() {
+        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
+        MetaObject metaObject = SystemMetaObject.forObject(paginationInterceptor);
+        Assertions.assertFalse((Boolean) metaObject.getValue("overflow"));
+        Properties properties = new Properties();
+        properties.setProperty("overflow", "true");
+        paginationInterceptor.setProperties(properties);
+        Assertions.assertTrue((Boolean) metaObject.getValue("overflow"));
+        paginationInterceptor.setOverflow(false);
+        Assertions.assertFalse((Boolean) metaObject.getValue("overflow"));
+    }
+    
+    @Test
+    void testSetDbType() {
+        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
+        MetaObject metaObject = SystemMetaObject.forObject(paginationInterceptor);
+        Assertions.assertNull(metaObject.getValue("dialectType"));
+        Properties properties = new Properties();
+        properties.setProperty("dialectType", "mysql");
+        paginationInterceptor.setProperties(properties);
+        Assertions.assertEquals(DbType.MYSQL, metaObject.getValue("dbType"));
+        paginationInterceptor.setDbType(DbType.DB2);
+        Assertions.assertEquals(DbType.DB2, metaObject.getValue("dbType"));
+        paginationInterceptor.setDialectType("mysql");
+        Assertions.assertEquals(DbType.MYSQL, metaObject.getValue("dbType"));
+    }
+    
+    @Test
+    void testSetDialect() {
+        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
+        MetaObject metaObject = SystemMetaObject.forObject(paginationInterceptor);
+        Assertions.assertNull(metaObject.getValue("dialectClazz"));
+        Properties properties = new Properties();
+        properties.setProperty("dialectClazz", MySqlDialect.class.getName());
+        paginationInterceptor.setProperties(properties);
+        Assertions.assertEquals(MySqlDialect.class.getName(), metaObject.getValue("dialect").getClass().getName());
+        paginationInterceptor.setDialect(new DB2Dialect());
+        Assertions.assertEquals(DB2Dialect.class.getName(), metaObject.getValue("dialect").getClass().getName());
+        paginationInterceptor.setDialectClazz(MySqlDialect.class.getName());
+        Assertions.assertEquals(MySqlDialect.class.getName(), metaObject.getValue("dialect").getClass().getName());
+    }
+    
+    @Test
+    void testSetLimit(){
+        PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
+        MetaObject metaObject = SystemMetaObject.forObject(paginationInterceptor);
+        Assertions.assertEquals(500L, metaObject.getValue("limit"));
+        Properties properties = new Properties();
+        properties.setProperty("limit", "10086");
+        paginationInterceptor.setProperties(properties);
+        Assertions.assertEquals(10086L, metaObject.getValue("limit"));
+        paginationInterceptor.setLimit(10010L);
+        Assertions.assertEquals(10010L, metaObject.getValue("limit"));
+    }
+    
+}