shardingsphere如何支持utf8mb4

我们在使用mysql的过程中，由于业务需求，在创建database中有时候需要支持特殊表情符号存储，比较直接简单的方式就是设置database的编码格式为utf8mb4

那么在使用shardingsphere进行分表分库的时候，如何让shardingsphere也支持utf8mb4呢？

查看shardingsphere的源码，我们可以看到shardingsphere对于datasource进行了二次封装，目前使用的shardingsphere-4.0.0-RC1这个版本中，如果需要对于utf8mb4需要我们对源码进行二次开发

1、创建springboot工程

可以直接使用Spring Initializr生成项目

2、添加依赖关系

    org.apache.shardingsphere
    sharding-jdbc-spring-boot-starter
    4.0.0-RC1

3、在application.properties文件中配置添加如下：

spring.shardingsphere.datasource.ds0.connection-init-sqls = set names utf8mb4;

4、重写org.apache.shardingsphere.shardingjdbc.spring.boot.util.DataSourceUtil

我们先把shardingsphere的DataSourceUtil的源码贴出来

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.shardingsphere.shardingjdbc.spring.boot.util;

import com.google.common.base.CaseFormat;
import com.google.common.collect.Sets;
import lombok.AccessLevel;
import lombok.NoArgsConstructor;

import javax.sql.DataSource;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Data source utility class.
 *
 * @author zhangliang
 */
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public final class DataSourceUtil {
    
    private static final String SET_METHOD_PREFIX = "set";
    
    private static Collection> generalClassType;
    
    static {
        generalClassType = Sets.>newHashSet(boolean.class, Boolean.class, int.class, Integer.class, long.class, Long.class, String.class);
    }
    
    /**
     * Get data source.
     *
     * @param dataSourceClassName data source class name
     * @param dataSourceProperties data source properties
     * @return data source instance
     * @throws ReflectiveOperationException reflective operation exception
     */
    public static DataSource getDataSource(final String dataSourceClassName, final Map dataSourceProperties) throws ReflectiveOperationException {
        DataSource result = (DataSource) Class.forName(dataSourceClassName).newInstance();
        for (Entry entry : dataSourceProperties.entrySet()) {
            callSetterMethod(result, getSetterMethodName(entry.getKey()), null == entry.getValue() ? null : entry.getValue().toString());
        }
        return result;
    }
    
    private static String getSetterMethodName(final String propertyName) {
        if (propertyName.contains("-")) {
            return CaseFormat.LOWER_HYPHEN.to(CaseFormat.LOWER_CAMEL, SET_METHOD_PREFIX + "-" + propertyName);
        }
        return SET_METHOD_PREFIX + String.valueOf(propertyName.charAt(0)).toUpperCase() + propertyName.substring(1, propertyName.length());
    }
    
    private static void callSetterMethod(final DataSource dataSource, final String methodName, final String setterValue) {
        for (Class each : generalClassType) {
            try {
                Method method = dataSource.getClass().getMethod(methodName, each);
                if (boolean.class == each || Boolean.class == each) {
                    method.invoke(dataSource, Boolean.valueOf(setterValue));
                } else if (int.class == each || Integer.class == each) {
                    method.invoke(dataSource, Integer.parseInt(setterValue));
                } else if (long.class == each || Long.class == each) {
                    method.invoke(dataSource, Long.parseLong(setterValue));
                } else {
                    method.invoke(dataSource, setterValue);
                }
                return;
            } catch (final ReflectiveOperationException ignored) {
            }
        }
    }
}

我们可以发现generalClassType 对于集合类型并不支持，而我们需要设置的connection-init-sqls = set names utf8mb4，在datasource源码中是用集合来接收的，这个时候，我们就需要修改shardingsphere的DataSourceUtil源码，让其也支持Collection类型

首先，在generalClassType的初始化变量中添加对于集合的支持

static {
        generalClassType = Sets.>newHashSet(boolean.class, Boolean.class, int.class, Integer.class, long.class, Long.class, String.class, Collection.class);
    }

对于callSetterMethod方法，我们需要改造

private static void callSetterMethod(final DataSource dataSource, final String methodName, final String setterValue) {
        for (Class each : generalClassType) {
            try {
                Method method = dataSource.getClass().getMethod(methodName, each);
                if (boolean.class == each || Boolean.class == each) {
                    method.invoke(dataSource, Boolean.valueOf(setterValue));
                } else if (int.class == each || Integer.class == each) {
                    method.invoke(dataSource, Integer.parseInt(setterValue));
                } else if (long.class == each || Long.class == each) {
                    method.invoke(dataSource, Long.parseLong(setterValue));
                } else if (Collection.class == each) {
                    String[] setterValues = setterValue.split(",");
                    method.invoke(dataSource, Arrays.asList(setterValues));
                } else {
                    method.invoke(dataSource, setterValue);
                }
                return;
            } catch (final ReflectiveOperationException ignored) {
            }
        }
    }

完整的代码如下改造如下：

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.shardingsphere.shardingjdbc.spring.boot.util;

import com.google.common.base.CaseFormat;
import com.google.common.collect.Sets;
import lombok.AccessLevel;
import lombok.NoArgsConstructor;

import javax.sql.DataSource;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.Collection;
import java.util.Map;
import java.util.Map.Entry;

/**
 * Data source utility class.
 *
 * @author zhangliang
 */
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public final class DataSourceUtil {

    private static final String SET_METHOD_PREFIX = "set";

    private static Collection> generalClassType;

    static {
        generalClassType = Sets.>newHashSet(boolean.class, Boolean.class, int.class, Integer.class, long.class, Long.class, String.class, Collection.class);
    }

    /**
     * Get data source.
     *
     * @param dataSourceClassName data source class name
     * @param dataSourceProperties data source properties
     * @return data source instance
     * @throws ReflectiveOperationException reflective operation exception
     */
    public static DataSource getDataSource(final String dataSourceClassName, final Map dataSourceProperties) throws ReflectiveOperationException {
        DataSource result = (DataSource) Class.forName(dataSourceClassName).newInstance();
        for (Entry entry : dataSourceProperties.entrySet()) {
            callSetterMethod(result, getSetterMethodName(entry.getKey()), null == entry.getValue() ? null : entry.getValue().toString());
        }
        return result;
    }

    private static String getSetterMethodName(final String propertyName) {
        if (propertyName.contains("-")) {
            return CaseFormat.LOWER_HYPHEN.to(CaseFormat.LOWER_CAMEL, SET_METHOD_PREFIX + "-" + propertyName);
        }
        return SET_METHOD_PREFIX + String.valueOf(propertyName.charAt(0)).toUpperCase() + propertyName.substring(1, propertyName.length());
    }

    private static void callSetterMethod(final DataSource dataSource, final String methodName, final String setterValue) {
        for (Class each : generalClassType) {
            try {
                Method method = dataSource.getClass().getMethod(methodName, each);
                if (boolean.class == each || Boolean.class == each) {
                    method.invoke(dataSource, Boolean.valueOf(setterValue));
                } else if (int.class == each || Integer.class == each) {
                    method.invoke(dataSource, Integer.parseInt(setterValue));
                } else if (long.class == each || Long.class == each) {
                    method.invoke(dataSource, Long.parseLong(setterValue));
                } else if (Collection.class == each) {
                    String[] setterValues = setterValue.split(",");
                    method.invoke(dataSource, Arrays.asList(setterValues));
                } else {
                    method.invoke(dataSource, setterValue);
                }
                return;
            } catch (final ReflectiveOperationException ignored) {
            }
        }
    }
}

最后测试，这里我省略不写