<pre name="code" class="java">import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.List;
import java.util.Vector;

import org.apache.commons.lang3.reflect.FieldUtils;
/**
 * @author Gary Huang
 * 博客地址：http://blog.csdn.net/hfmbook/article/details/41290641
 * 
 * */
public class UpdateSql {
	private Object target ; 
	
	private String idName ; 
	
	private Object idValue ; 
	
	private SqlType currentType ; 
	
	public enum SqlType {
		INSERT, UPDATE, DELETE 
	}
	
	public UpdateSql(SqlType sqlType, Object target) {
		this.target = target ; 
		switch (sqlType) {
		case INSERT:
			currentType = SqlType.INSERT ;
			createInsert(); 
			break;  
		case UPDATE:
			currentType = SqlType.UPDATE ;
			createUpdate() ; 
			break;
		case DELETE:
			currentType = SqlType.DELETE ;
			createDelete() ;  
			break ;
		}
	}
	/**
	 * 创建跟删除
	 * */
	private void createDelete() {
		String tableName = getTableName() ;
		Field[] fields = target.getClass().getDeclaredFields() ;
		StringBuffer sqlBuffer = new StringBuffer() ; 
		sqlBuffer.append("DELETE FROM ").append(tableName).append(" WHERE ") ;
		for(Field field : fields){
			if(!Modifier.isStatic(field.getModifiers())){
				ID id = field.getAnnotation(ID.class);
				if(null != id){
					sqlBuffer.append( field.getName()).append("=?");
					param.add(readField(field));
				}
			}
		}
		this.sqlBuffer = sqlBuffer.toString();
	}
	
	
	public Object readField(Field field ){
		try {
			return FieldUtils.readField( field , target, true )  ; 
		} catch (Exception e) {
			throw new RuntimeException( currentType.name() ,e ) ;
		}
	}
	
	/**
	 * 创建跟新语句
	 * */
	private void createUpdate() {
		String tableName = getTableName() ;
		Field[] fields = target.getClass().getDeclaredFields() ;
		StringBuffer sqlBuffer = new StringBuffer() ; 
		sqlBuffer.append("UPDATE ").append(tableName).append(" SET ") ; 
		 
			for(Field field : fields){
				if(!Modifier.isStatic(field.getModifiers())){
					ID id = field.getAnnotation(ID.class);
					if(id == null){
						sqlBuffer.append( field.getName()).append("=?") ; 
						param.add( readField(field)  ) ;  
					}else{
						idName = field.getName() ; 
						idValue = http://www.mamicode.com/readField(field)   ; >

java 根据实体对象生成 增删改的SQL语句