介绍了hibernate的入门有一些基本常用的事例

				//$Id: Update.java,v 1.4 2005/02/12 07:19:46 steveebersole Exp $				package org.hibernate.sql;								import java.util.Iterator;				import java.util.Map;								import org.hibernate.type.LiteralType;				import org.hibernate.util.StringHelper;								import org.apache.commons.collections.SequencedHashMap;								/**				 * An SQL UPDATE statement				 *				 * @author Gavin King				 */				public class Update {									private String tableName;					private String[] primaryKeyColumnNames;					private String versionColumnName;					private String where;									private String comment;					public Update setComment(String comment) {						this.comment = comment;						return this;					}									private Map columns = new SequencedHashMap();					private Map whereColumns = new SequencedHashMap();									public Update addColumns(String[] columnNames) {						for ( int i=0; i							addColumn( columnNames[i] );						}						return this;					}									public Update addColumns(String[] columnNames, boolean[] updateable) {						for ( int i=0; i							if ( updateable[i] ) addColumn( columnNames[i] );						}						return this;					}									public Update addColumns(String[] columnNames, String value) {						for ( int i=0; i							addColumn( columnNames[i], value );						}						return this;					}									public Update addColumn(String columnName) {						return addColumn(columnName, "?");					}									public Update addColumn(String columnName, String value) {						columns.put(columnName, value);						return this;					}									public Update addColumn(String columnName, Object value, LiteralType type) throws Exception {						return addColumn( columnName, type.objectToSQLString(value) );					}									public Update addWhereColumns(String[] columnNames) {						for ( int i=0; i							addWhereColumn( columnNames[i] );						}						return this;					}									public Update addWhereColumns(String[] columnNames, String value) {						for ( int i=0; i							addWhereColumn( columnNames[i], value );						}						return this;					}									public Update addWhereColumn(String columnName) {						return addWhereColumn(columnName, "=?");					}									public Update addWhereColumn(String columnName, String value) {						whereColumns.put(columnName, value);						return this;					}									public Update setTableName(String tableName) {						this.tableName = tableName;						return this;					}									public Update setWhere(String where) {						this.where=where;						return this;					}									public String toStatementString() {						StringBuffer buf = new StringBuffer( columns.size()*15 + tableName.length() + 10 );						if (comment!=null) buf.append("/*").append(comment).append("*/");						buf.append("update ")							.append(tableName)							.append(" set ");						Iterator iter = columns.entrySet().iterator();						while ( iter.hasNext() ) {							Map.Entry e = (Map.Entry) iter.next();							buf.append( e.getKey() )								.append('=')								.append( e.getValue() );							if ( iter.hasNext() ) buf.append(", ");						}						buf.append(" where ")							.append( StringHelper.join("=? and ", primaryKeyColumnNames) )							.append("=?");						if (where!=null) {							buf.append(" and ")								.append(where);						}						iter = whereColumns.entrySet().iterator();						while ( iter.hasNext() ) {							Map.Entry e = (Map.Entry) iter.next();							buf.append(" and ")								.append( e.getKey() )								.append( e.getValue() );						}						if (versionColumnName!=null) {							buf.append(" and ")								.append(versionColumnName)								.append("=?");						}						return buf.toString();					}									public Update setPrimaryKeyColumnNames(String[] primaryKeyColumnNames) {						this.primaryKeyColumnNames = primaryKeyColumnNames;						return this;					}									public Update setVersionColumnName(String versionColumnName) {						this.versionColumnName = versionColumnName;						return this;					}								}