MyBatis 分页代码实现
来源：互联网 发布：星际战甲库伯数据模块 编辑：程序博客网 时间：2024/06/05 18:53
/**
* 数据库方言接口
* @author Administrator
*
*/
public interface Dialect {
public static enum Type {
MYSQL {
public String getValue(){return "mysql";}
},
SQLSERVER {
public String getValue() {return "sqlserver";}
},
ORACLE {
public String getValue() {return "oracle";}
};
public abstract String getValue();
}
/**
* 获取分页sql
* @param sql 原始查询sql
* @param offset 开始记录索引（从0开始计数）
* @param limit 每页记录大小
* @return 数据库相关的分页sql
*/
public String getPaginationSql(String sql, int offset, int limit);
}
public class MySQL5Dialect implements Dialect {
@Override
public String getPaginationSql(String sql, int offset, int limit) {
return sql + " limit " + offset + "," + limit;
}
}
public class SqlServerDialect implements Dialect {
@Override
public String getPaginationSql(String sql, int pageNo, int pageSize) {
return "select top " + pageSize + " from (" + sql
+ ") t where t.id not in (select top " + (pageNo-1)*pageSzie + " t1.id from ("
+ sql + ") t1)";
}
}
public class OrcaleDialect implements Dialect {
@Override
public String getPaginationSql(String sql, int paheNo, int pageSize) {
return "select * from (select rownum rn, t.* from (" + sql
+ ") t where rownum <= " + (pageNo* pageSize)
+ ") t1 where t1.rn > " + ((pageNo- 1) * pageSize);
}
}
@Intercepts({@Signature(type=StatementHandler.class,method="prepare",args={Connection.class})})
public class PaginationInterceptor implements Interceptor {
private final static Log log = LogFactory.getLog(PaginationInterceptor.class);
@Override
public Object intercept(Invocation invocation) throws Throwable {
StatementHandler statmentHandler = (StatementHandler) invocation.getTarget();
BoundSql boundSql = statmentHandler.getBoundSql();
MetaObject metaStatementHandler = MetaObject.forObject(statmentHandler);
RowBounds rowBounds = (RowBounds) metaStatementHandler.getValue("delegate.rowBounds");
if(rowBounds == null || rowBounds == RowBounds.DEFAULT) {
return invocation.proceed();
}
Configuration configuration = (Configuration) metaStatementHandler
.getValue("delegate.configuration");
Dialect.Type databaseType = null;
try{
databaseType = Dialect.Type.valueOf(configuration.getVariables()
.getProperty("dialect").toUpperCase());
} catch(Exception e){
throw new ConfigurationException(
"the value of the dialect property in mybatis-config.xml is not defined : "
+ configuration.getVariables().getProperty("dialect"));
}
Dialect dialect =null;
switch(databaseType){
case MYSQL: dialect =new MySQL5Dialect();
case SQLSERVER : dialect = new SqlServerDialect();
case ORACLE : dialect = new OrcaleDialect();
}
String originalSql = (String)metaStatementHandler.getValue("delegate.boundSql.sql");
metaStatementHandler.setValue("delegate.boundSql.sql", dialect.getPaginationSql(originalSql,
rowBounds.getOffset(), rowBounds.getLimit()) );
metaStatementHandler.setValue("delegate.rowBounds.offset", RowBounds.NO_ROW_OFFSET );
metaStatementHandler.setValue("delegate.rowBounds.limit", RowBounds.NO_ROW_LIMIT );
if(log.isDebugEnabled()){
log.debug("生成分页SQL : "+ boundSql.getSql());
}
return invocation.proceed();
}
@Override
public Object plugin(Object target) {
return Plugin.wrap(target, this);
}
@Override
public void setProperties(Properties properties) {
// TODO Auto-generated method stub
}
}
public class PaginationHelper {
public static int getRowCount(SqlSession sqlSession, String statementName, Object values) {
Map parameterMap = toParameterMap(values);
int count = 0;
try {
MappedStatement mst = sqlSession.getConfiguration().getMappedStatement(statementName);
BoundSql boundSql = mst.getBoundSql(parameterMap);
String sql = " select count(1) row_count from (" + boundSql.getSql() + ") ";
PreparedStatement pstmt = sqlSession.getConnection().prepareStatement(sql);
setParameters(pstmt, mst, boundSql, parameterMap);
ResultSet rs = pstmt.executeQuery();
if (rs.next()) {
count = rs.getInt("row_count");
}
rs.close();
pstmt.close();
} catch (Exception e) {
count = 0;
throw new RuntimeException(e);
}
return count;
}
private static void setParameters(PreparedStatement ps, MappedStatement mappedStatement,
BoundSql boundSql, Object parameterObject) throws SQLException {
ErrorContext.instance().activity("setting parameters")
.object(mappedStatement.getParameterMap().getId());
List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
if (parameterMappings != null) {
Configuration configuration = mappedStatement.getConfiguration();
TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
MetaObject metaObject = parameterObject == null ? null : configuration
.newMetaObject(parameterObject);
for (int i = 0; i < parameterMappings.size(); i++) {
ParameterMapping parameterMapping = parameterMappings.get(i);
if (parameterMapping.getMode() != ParameterMode.OUT) {
Object value;
String propertyName = parameterMapping.getProperty();
PropertyTokenizer prop = new PropertyTokenizer(propertyName);
if (parameterObject == null) {
value = null;
} else if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
value = parameterObject;
} else if (boundSql.hasAdditionalParameter(propertyName)) {
value = boundSql.getAdditionalParameter(propertyName);
} else if (propertyName.startsWith(ForEachSqlNode.ITEM_PREFIX)
&& boundSql.hasAdditionalParameter(prop.getName())) {
value = boundSql.getAdditionalParameter(prop.getName());
if (value != null) {
value = configuration.newMetaObject(value)
.getValue(propertyName.substring(prop.getName().length()));
}
} else {
value = metaObject == null ? null : metaObject.getValue(propertyName);
}
TypeHandler typeHandler = parameterMapping.getTypeHandler();
if (typeHandler == null) {
throw new ExecutorException("There was no TypeHandler found for parameter "
+ propertyName + " of statement " + mappedStatement.getId());
}
typeHandler.setParameter(ps, i + 1, value, parameterMapping.getJdbcType());
}
}
}
}
protected static Map toParameterMap(Object parameter) {
if (parameter == null) {
return new HashMap();
}
if (parameter instanceof Map) {
return (Map<?, ?>) parameter;
} else {
try {
return PropertyUtils.describe(parameter);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
}
}
public class Pager implements Serializable{
private static final long serialVersionUID = 1566826618769972857L;
//默认的每页记录数
public static final int DEFAULT_PAGE_SIZE = 25;
// 每页的记录数
private int pageSize = DEFAULT_PAGE_SIZE;
// 当前页
private int pageNo = 1;
// 总行数
private int rowCount;
// 总页数
private int pageCount;
// 每页的记录
private List resultList;
public Pager() {
}
public Pager(int pageNo) {
this.pageNo = pageNo;
}
public Pager(int pageSize, int pageNo) {
this.pageSize = pageSize;
this.pageNo = pageNo;
}
public int getPageSize() {
return pageSize;
}
public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public int getPageNo() {
return pageNo;
}
public void setPageNo(int pageNo) {
this.pageNo = pageNo;
}
public int getRowCount() {
return rowCount;
}
public void setRowCount(int rowCount) {
this.rowCount = rowCount;
if(rowCount % pageSize == 0) {
this.pageCount = rowCount / pageSize;
} else {
this.pageCount = rowCount / pageSize + 1;
}
}
public int getPageCount() {
return pageCount;
}
public void setPageCount(int pageCount) {
this.pageCount = pageCount;
}
public List getResultList() {
return resultList;
}
public void setResultList(List resultList) {
this.resultList = resultList;
}
}
public class SqlSessionWrapper {
private SqlSession sqlSession;
public SqlSessionWrapper(SqlSession sqlSession) {
this.sqlSession = sqlSession;
}
...
public Pager selectPagination(String s, Object param, Pager pager) {
if(pager == null) {
pager = new Pager();
}
List resultList = sqlSession.selectList(s, param,
new RowBounds(pager.getPageNo(), pager.getPageSize()));
int rowCount = PaginationHelper.getRowCount(sqlSession, s, param);
pager.setResultList(resultList);
pager.setRowCount(rowCount);
if(resultList == null || resultList.size() == 0) {
pager.setPageCount(0);
pager.setPageNo(0);
}
return pager;
}
public Pager selectPagination(String s, Pager pager) {
return selectPagination(s, null, pager);
}
...
}
- MyBatis 分页代码实现
- mybatis分页插件实现分页
- Mybatis+pageHelper 实现mybatis分页
- mybatis 分页实现
- mybatis 后台分页实现
- Mybatis实现物理分页
- Mybatis 实现物理分页
- mybatis分页实现1
- mybatis分页实现2
- MyBatis分页实现 - Oracle
- Mybatis分页实现流程
- Mybatis实现物理分页
- mybatis+spring实现分页
- MyBatis分页功能实现
- mybatis分页的实现
- Mybatis之实现分页
- Mybatis分页实现
- MyBatis插件实现分页
- 张孝祥整理的JAVA面试题目（八）（每天一更)
- CentOS──xxx is not in the sudoers file解决方法
- Basic Level 1012. 数字分类 (20)
- map获取输入文件名称和GenericOptionsParser使用
- 如何在代码中设置imageview的大小
- MyBatis 分页代码实现
- 子数组合并算法之向右循环
- 基本配置及安全级别security-level
- vs2010编译boost c++库 && blitz++
- Memcached源码分析之网络连接建立
- LInux 描述符GDT, IDT & LDT结构定义
- 《C++ Primer第五版》读书笔记--插播--宏相对于inline的优势
- svn: Could not use external editor to fetch log message; 问题解决
- (转)Android动画学习笔记-Android Animation
