ShardingSphere问题解决（一）

素颜马尾好姑娘i 2023-02-09 13:25 11阅读 0赞

## 概要：错误信息 Data sources cannot be empty ##

*  **shardingSphere版本**  
    shardingshpere\_version=4.1.0  
    sharding\_jdbc\_spring\_namespace\_version=4.1.0

compile("org.apache.shardingsphere:sharding-jdbc-spring-boot-starter:${ shardingshpere_version}")
    compile("org.apache.shardingsphere:sharding-jdbc-spring-namespace:${ sharding_jdbc_spring_namespace_version}")

*  **详细异常明细**

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'shardingDataSource' threw exception; nested exception is java.lang.IllegalArgumentException: Data sources cannot be empty.
     at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
     at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:582)
     ... 104 common frames omitted
    Caused by: java.lang.IllegalArgumentException: Data sources cannot be empty.
     at com.google.common.base.Preconditions.checkArgument(Preconditions.java:134)
     at org.apache.shardingsphere.core.rule.ShardingRule.<init>(ShardingRule.java:76)
     at org.apache.shardingsphere.shardingjdbc.api.ShardingDataSourceFactory.createDataSource(ShardingDataSourceFactory.java:48)
     at org.apache.shardingsphere.shardingjdbc.spring.boot.SpringBootConfiguration.shardingDataSource(SpringBootConfiguration.java:103)
     at org.apache.shardingsphere.shardingjdbc.spring.boot.SpringBootConfiguration$$EnhancerBySpringCGLIB$$a2810b5d.CGLIB$shardingDataSource$1(<generated>)
     at org.apache.shardingsphere.shardingjdbc.spring.boot.SpringBootConfiguration$$EnhancerBySpringCGLIB$$a2810b5d$$FastClassBySpringCGLIB$$b2e37f70.invoke(<generated>)
     at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
     at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:361)
     at org.apache.shardingsphere.shardingjdbc.spring.boot.SpringBootConfiguration$$EnhancerBySpringCGLIB$$a2810b5d.shardingDataSource(<generated>)
     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     at java.lang.reflect.Method.invoke(Method.java:497)
     at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
     ... 105 common frames omitted

*  **查看源码**  
    **ShardingRule.class**，发现 **dataSourceNames** 节点为空

public ShardingRule(final ShardingRuleConfiguration shardingRuleConfig, final Collection<String> dataSourceNames) { 
        Preconditions.checkArgument(null != shardingRuleConfig, "ShardingRuleConfig cannot be null.");
    
    	Preconditions.checkArgument(null != dataSourceNames && !dataSourceNames.isEmpty(), "Data sources cannot be empty.");
    	    this.ruleConfiguration = shardingRuleConfig;
    	
    	shardingDataSourceNames = new ShardingDataSourceNames(shardingRuleConfig, dataSourceNames);
    	
    	tableRules = createTableRules(shardingRuleConfig);
    	
    	broadcastTables = shardingRuleConfig.getBroadcastTables();
    	
    	bindingTableRules = createBindingTableRules(shardingRuleConfig.getBindingTableGroups());
    	
    	defaultDatabaseShardingStrategy = createDefaultShardingStrategy(shardingRuleConfig.getDefaultDatabaseShardingStrategyConfig());
    	
    	defaultTableShardingStrategy = createDefaultShardingStrategy(shardingRuleConfig.getDefaultTableShardingStrategyConfig());
    	
    	defaultShardingKeyGenerator = createDefaultKeyGenerator(shardingRuleConfig.getDefaultKeyGeneratorConfig());
    	
    	masterSlaveRules = createMasterSlaveRules(shardingRuleConfig.getMasterSlaveRuleConfigs());
    	
    	encryptRule = createEncryptRule(shardingRuleConfig.getEncryptRuleConfig());
    }

反调至**SpringBootConfiguration.class**，发现数据源信息取自**dataSourceMap**

@Bean
    @Conditional(ShardingRuleCondition.class)
    public DataSource shardingDataSource() throws SQLException { 
    
    	return ShardingDataSourceFactory.createDataSource(dataSourceMap, new ShardingRuleConfigurationYamlSwapper().swap(shardingRule), props.getProps());
    }

而**dataSourceMap**赋值逻辑为

@Override
    public final void setEnvironment(final Environment environment) { 
        String prefix = "spring.shardingsphere.datasource.";
        for (String each : getDataSourceNames(environment, prefix)) { 
    
    		try { 
    		
    			dataSourceMap.put(each, getDataSource(environment, prefix, each));
    		
    		} catch (final ReflectiveOperationException ex) { 
    		
    			throw new ShardingSphereException("Can't find datasource type!", ex);
    		
    		} catch (final NamingException namingEx) { 
    		
    			throw new ShardingSphereException("Can't find JNDI datasource!", namingEx);
    		
    		}
    	}
    }

从而可知数据源yaml配置文件因该为：**spring.shardingsphere.datasource.**  
而自己的项目配置为**sharding.dataSource**

加载配置文件时没有问题，可以注入数据源和路由规则，当 @Conditional(ShardingRuleCondition.class) 生效时，会在环境中重新加载默认路径数据源，导致启动失败。

*  **解决方案**：  
    配置默认数据源路径即可