标签：style io os ar java for strong sp 文件
import com.mybatis.page.support.PageSqlGenerator;
import com.mybatis.page.support.OraclePagerSqlGenerator;
import com.mybatis.page.support.PageRowBounds;
import org.apache.ibatis.executor.Executor;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.SqlSource;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.session.RowBounds;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Properties;
@Intercepts(@Signature(type = Executor.class, method = "query", args = {MappedStatement.class, Object.class, RowBounds.class, ResultHandler.class}))
public class PagePlugin implements Interceptor {
private static PageSqlGenerator sqlGenerator = new OraclePagerSqlGenerator();
@Override
public Object intercept(Invocation invocation) throws Throwable {
final Object[] args = invocation.getArgs();
RowBounds rowBounds = (RowBounds) args[2];
if (rowBounds instanceof PageRowBounds) {
Executor executor = (Executor) invocation.getTarget();
MappedStatement mappedStatement = (MappedStatement) args[0];
Object parameter = args[1];
PageRowBounds pageRowBounds = (PageRowBounds) args[2];
ResultHandler resultHandler = (ResultHandler) args[3];
BoundSql boundSql = mappedStatement.getBoundSql(parameter);
PageSqlSqlSource sqlSource = new PageSqlSqlSource(boundSql);
MappedStatement statement = buildMappedStatement(mappedStatement, sqlSource);
MetaObject msObject = SystemMetaObject.forObject(statement);
msObject.setValue("sqlSource.boundSql.sql", sqlGenerator.getPagerSql(boundSql.getSql(), rowBounds));
args[0] = statement;
StatementHandler statementHandler = mappedStatement.getConfiguration().newStatementHandler(executor, mappedStatement, parameter, rowBounds, resultHandler, boundSql);
ResultSet rs = null;
try (PreparedStatement stmt = executor.getTransaction().getConnection().prepareStatement(sqlGenerator.getCountSql(boundSql.getSql()))) {
statementHandler.parameterize(stmt);
rs = stmt.executeQuery();
int totalCount = 0;
if (rs.next()) {
totalCount = rs.getInt("totalCount");
}
pageRowBounds.setTotalCount(totalCount);
} finally {
if (rs != null) {
try {
rs.close();
} catch (Throwable ignored) {
}
}
}
}
return invocation.proceed();
}
@Override
public Object plugin(Object target) {
if (target instanceof Executor) {
return Plugin.wrap(target, this);
} else {
return target;
}
}
@Override
public void setProperties(Properties properties) {}
private class PageSqlSqlSource implements SqlSource {
BoundSql boundSql;
public PageSqlSqlSource(BoundSql boundSql) {
this.boundSql = boundSql;
}
public BoundSql getBoundSql(Object parameterObject) {
return boundSql;
}
}
private MappedStatement buildMappedStatement(MappedStatement ms, SqlSource sqlSource) {
MappedStatement.Builder builder = new MappedStatement.Builder(ms.getConfiguration(), ms.getId(), sqlSource, ms.getSqlCommandType());
builder.resource(ms.getResource());
builder.fetchSize(ms.getFetchSize());
builder.statementType(ms.getStatementType());
builder.keyGenerator(ms.getKeyGenerator());
if (ms.getKeyProperties() != null && ms.getKeyProperties().length != 0) {
StringBuilder keyProperties = new StringBuilder();
for (String keyProperty : ms.getKeyProperties()) {
keyProperties.append(keyProperty).append(",");
}
keyProperties.delete(keyProperties.length() - 1, keyProperties.length());
builder.keyProperty(keyProperties.toString());
}
builder.timeout(ms.getTimeout());
builder.parameterMap(ms.getParameterMap());
builder.resultMaps(ms.getResultMaps());
builder.resultSetType(ms.getResultSetType());
builder.cache(ms.getCache());
builder.flushCacheRequired(ms.isFlushCacheRequired());
builder.useCache(ms.isUseCache());
return builder.build();
}
}
import org.apache.ibatis.session.RowBounds;
public class PageRowBounds extends RowBounds {
public final static int NO_TOTAL_COUNT = -1;
private int totalCount = NO_TOTAL_COUNT;
public PageRowBounds() {
super();
}
public PageRowBounds(int offset, int limit) {
super(offset, limit);
}
public void setTotalCount(int totalCount) {
this.totalCount = totalCount;
}
public int getTotalCount() {
return totalCount;
}
}
import org.apache.ibatis.session.RowBounds;
public interface PageSqlGenerator {
public String getPagerSql(String sql, RowBounds rowBounds);
public String getCountSql(String sql);
}
import org.apache.ibatis.session.RowBounds;
public class OraclePagerSqlGenerator implements PageSqlGenerator {
public String getPagerSql(String sql, RowBounds rowBounds) {
if (rowBounds.getLimit() == Integer.MAX_VALUE) {
return sql;
} else {
return getPagerSql(sql, rowBounds.getOffset(), rowBounds.getLimit());
}
}
public String getPagerSql(String sql, int offset, int limit) {
return "select * from (select inrow.*, rownum rn from (" + sql + ") inrow where rownum <=" + (limit + offset) + ") where rn >= " + offset;
}
public String getCountSql(String sql) {
return "select count(*) totalCount from (" + sql + ")";
}
}
配置文件
在mybatis配置文件中添加
<plugins> <plugin interceptor="com.mybatis.page.plugins.PagePlugin"/> </plugins>
测试代码
@Test
public void testPage() throws Exception {
PageRowBounds pageRowBounds = new PageRowBounds(0,3);
HashMap<String,String> hashMap = Maps.newHashMap();
hashMap.put("name","男");
List<Student> students = sqlSession.selectList("com.mybatis.mapper.StudentMapper.page",hashMap,pageRowBounds);
System.out.println(pageRowBounds.getTotalCount());
students.forEach(System.out::println);
pageRowBounds = new PageRowBounds(0,5);
students = sqlSession.selectList("com.mybatis.mapper.StudentMapper.page",hashMap,pageRowBounds);
System.out.println(pageRowBounds.getTotalCount());
for(Student student : students){
System.out.println(student);
}
}
总结：随便写写的，嘿嘿。
标签：style io os ar java for strong sp 文件
原文地址：http://my.oschina.net/u/726057/blog/336073
