统一异常 DataAccessException

 Spring 会将常见的数据库操(mysql、Oracle、db2…)作异常转换为自己的异常 DataAccessException，因此无论使用何种数据访问方式，都能使用一样的异常。

定制错误码

sql-error-codes.xml

 1<?xml version="1.0" encoding="UTF-8"?>
 2<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd">
 3
 4<beans>
 5
 6    <bean id="H2" class="org.springframework.jdbc.support.SQLErrorCodes">
 7        <!-- 复制spring官方sql-error-codes.xml 中 描述 H2 相关的错误码定义 -->
 8        <property name="badSqlGrammarCodes">
 9            <value>42000,42001,42101,42102,42111,42112,42121,42122,42132</value>
10        </property>
11        <property name="duplicateKeyCodes">
12            <value>23001,23505</value>
13        </property>
14        <property name="dataIntegrityViolationCodes">
15            <value>22001,22003,22012,22018,22025,23000,23002,23003,23502,23503,23506,23507,23513</value>
16        </property>
17        <property name="dataAccessResourceFailureCodes">
18            <value>90046,90100,90117,90121,90126</value>
19        </property>
20        <property name="cannotAcquireLockCodes">
21            <value>50200</value>
22        </property>
23
24        <!-- 自定义错误码解析逻辑 -->
25        <property name="customTranslations">
26            <bean class="org.springframework.jdbc.support.CustomSQLErrorCodesTranslation">
27                <property name="errorCodes" value="23001,23505" />
28                <!-- 当遇到"23001,23505" 这样的错误码时候，会抛出CustomDuplicatedKeyException异常-->
29                <property name="exceptionClass"
30                          value="geektime.spring.data.errorcodedemo.CustomDuplicatedKeyException" />
31            </bean>
32        </property>
33    </bean>
34
35</beans>

自定义异常 (违反唯一性约束的异常)
 CustomDuplicatedKeyException 必须是 DuplicateKeyException 的子类，否则 Spring 会报错。错误类型方向必须一致，异常的细节可以自定义。

 1package geektime.spring.data.errorcodedemo;
 2
 3import org.springframework.dao.DuplicateKeyException;
 4
 5public class CustomDuplicatedKeyException extends DuplicateKeyException {
 6    public CustomDuplicatedKeyException(String msg) {
 7        super(msg);
 8    }
 9
10    public CustomDuplicatedKeyException(String msg, Throwable cause) {
11        super(msg, cause);
12    }
13}

测试类

 1package geektime.spring.data.errorcodedemo;
 2
 3import org.junit.Test;
 4import org.junit.runner.RunWith;
 5import org.springframework.beans.factory.annotation.Autowired;
 6import org.springframework.boot.test.context.SpringBootTest;
 7import org.springframework.jdbc.core.JdbcTemplate;
 8import org.springframework.test.context.junit4.SpringRunner;
 9
10@RunWith(SpringRunner.class)
11@SpringBootTest
12public class ErrorCodeDemoApplicationTests {
13	@Autowired
14	private JdbcTemplate jdbcTemplate;
15
16	//预期异常CustomDuplicatedKeyException.class
17	@Test(expected = CustomDuplicatedKeyException.class)
18	public void testThrowingCustomException() {
19		//插入两条数据，主键相同，模拟 DuplicatedKeyException 异常
20		jdbcTemplate.execute("INSERT INTO FOO (ID, BAR) VALUES (1, 'a')");
21		jdbcTemplate.execute("INSERT INTO FOO (ID, BAR) VALUES (1, 'b')");
22	}
23}

测试结果

1Tests passed