请给出有一个ShardingSphere 使用的JAVA 例子
时间: 2024-05-02 10:21:04 浏览: 14
以下是一个简单的使用ShardingSphere实现分库分表的Java例子:
首先,需要在pom.xml文件中添加ShardingSphere的依赖:
```
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-core</artifactId>
<version>4.1.1</version>
</dependency>
```
接着,需要在Spring配置文件中添加ShardingSphere的数据源配置:
```
spring.shardingsphere.datasource.names=ds0, ds1
spring.shardingsphere.datasource.ds0.type=com.zaxxer.hikari.HikariDataSource
spring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds0.jdbc-url=jdbc:mysql://localhost:3306/db0?useUnicode=true&characterEncoding=utf-8
spring.shardingsphere.datasource.ds0.username=root
spring.shardingsphere.datasource.ds0.password=root
spring.shardingsphere.datasource.ds1.type=com.zaxxer.hikari.HikariDataSource
spring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds1.jdbc-url=jdbc:mysql://localhost:3306/db1?useUnicode=true&characterEncoding=utf-8
spring.shardingsphere.datasource.ds1.username=root
spring.shardingsphere.datasource.ds1.password=root
spring.shardingsphere.sharding.tables.user.actual-data-nodes=ds${0..1}.user_${0..1}
spring.shardingsphere.sharding.tables.user.table-strategy.standard.sharding-column=user_id
spring.shardingsphere.sharding.tables.user.table-strategy.standard.precise-algorithm-class-name=com.example.algorithm.ModuloShardingTableAlgorithm
spring.shardingsphere.sharding.tables.user.table-strategy.standard.range-algorithm-class-name=com.example.algorithm.RangeShardingTableAlgorithm
```
注意,上面的例子中使用了两个数据源ds0和ds1,分别对应了两个数据库db0和db1。同时,使用了ShardingSphere的分片表策略,将user表按照user_id字段进行分片,使用了ModuloShardingTableAlgorithm和RangeShardingTableAlgorithm算法来实现分片。
最后,需要实现两个算法类:
ModuloShardingTableAlgorithm.java:
```
public final class ModuloShardingTableAlgorithm implements PreciseShardingAlgorithm<Integer> {
@Override
public String doSharding(Collection<String> tableNames, PreciseShardingValue<Integer> shardingValue) {
for (String each : tableNames) {
if (each.endsWith(shardingValue.getValue() % tableNames.size() + "")) {
return each;
}
}
throw new IllegalArgumentException();
}
}
```
RangeShardingTableAlgorithm.java:
```
public final class RangeShardingTableAlgorithm implements RangeShardingAlgorithm<Integer> {
@Override
public Collection<String> doSharding(Collection<String> tableNames, RangeShardingValue<Integer> shardingValue) {
Collection<String> result = new LinkedHashSet<>();
for (Integer i = shardingValue.getValueRange().lowerEndpoint(); i <= shardingValue.getValueRange().upperEndpoint(); i++) {
for (String each : tableNames) {
if (each.endsWith(i % tableNames.size() + "")) {
result.add(each);
}
}
}
return result;
}
}
```
这样,就可以使用ShardingSphere实现分库分表了。