Struts2 中常用的代码

时间:2022-07-31 04:49:25

BaseAction

public class BaseAction extends ActionSupport {

	protected String target;

	public Map getRequest(){
return (Map)ActionContext.getContext().get("request");
} public Map getSession(){
return ActionContext.getContext().getSession();
} public Map getApplication(){
return ActionContext.getContext().getApplication();
} public HttpServletResponse getResponse(){
HttpServletResponse response = ServletActionContext.getResponse();
response.setContentType("text/html;charset=utf-8");
return response;
}

  DaoFactory

public class DaoFactory<T> {
private static String fname = "oracle.jdbc.driver.OracleDriver";
private static String url = "jdbc:oracle:thin:@localhost:1521:orcl";
private static String user = "scott";
private static String pwd = "tiger";
/**
* 加载数据库驱动
*/
static{
try {
Class.forName(fname);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 创建登陆对象,获取connection
* @return
*/
public Connection getConnection(){
try {
return DriverManager.getConnection(url,user,pwd);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
/**
* 设置preparedStatement对象参数
* @param ps
* @param params
* @throws SQLException
*/
public void setParams(PreparedStatement ps,Object[] params) throws SQLException{
if(params == null)return;
for(int i = 0; i < params.length; i++){
ps.setObject(i+1, params[i]);
}
}
/**
* 查询方法
* @param sql
* @param params
* @return
*/
public List<List> query(String sql,Object[] params) {
Connection con = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
ArrayList allData = new ArrayList();
try {
con = getConnection();
pstmt = con.prepareStatement(sql);
setParams(pstmt,params);
rs = pstmt.executeQuery();
int colCount = rs.getMetaData().getColumnCount();
while (rs.next()) {
ArrayList rowData = new ArrayList();
for (int i = 1; i <= colCount; i++) {
rowData.add(rs.getObject(i));
}
allData.add(rowData);
}
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
closeAll(rs,pstmt,con);
}
return allData;
}
/**
*
* @param sql 查询语句,要求句中字段名或别名必须和类中的属性名相同
* @param params sql语句所需的参数数组
* @param clazz 要封装的类的Class对象
* @return 返回封装好的对象,装载在集合中
* @throws Exception
*
*/
public List<T> list(String sql,Object[] params,Class clazz){
List<T> list=new ArrayList<T>();
Connection con=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
con = getConnection();
ps = con.prepareStatement(sql);
setParams(ps, params);
rs = ps.executeQuery();
ResultSetMetaData md=rs.getMetaData();
int colCount=md.getColumnCount();
String fieldName="";
Field field=null; while(rs.next()){
T obj=(T)clazz.newInstance();//实例化包装实体
for(int i=1;i<=colCount;i++){
fieldName=md.getColumnName(i);//获得数据库字段名
//System.out.println("字段名:====================="+ fieldName+"================" + rs.getString(i));
try {
field = clazz.getDeclaredField(fieldName);//获得实体类中和数据库字段名相应的Field对象
field.setAccessible(true);//设置Field的可访问性为true,否则私有属性不能访问
//System.out.println("字段类型:===================" + field.getType().getName()+"================");
field.set(obj, convert(rs.getString(i),field.getType()));
//调用Field的set方法给属性赋值
} catch (Exception e) { //如果没有相应的Field对象则不作任何处理 }
}
list.add(obj);
}
} catch (SQLException e) {
e.printStackTrace();
} catch (Exception e) { e.printStackTrace();
}finally{
closeAll(rs, ps, con);
}
return list;
}
/**
* 该方法用于返回多对一关系的集合
* @param sql 用于多表联合查询的语句,要求主类对应的字段前缀名必须和类名相同(不区分大小写),
* 引用类对应的字段前缀名必须和主类中引用的属性名相同(大小写严格区分)
* @param params 查询语句的参数数组
* @param clazzs 返回的封装对象,第一个是List中封装的主对象,其余为该对象的引用属性对象
* @return
* @throws Exception
*/
public List<T> list(String sql,Object[] params,Class...clazzs){
List<T> list=new ArrayList<T>();
Connection con=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
con = getConnection();
ps = con.prepareStatement(sql);
setParams(ps, params);
rs = ps.executeQuery();
ResultSetMetaData md=rs.getMetaData();
int colCount=md.getColumnCount();
System.out.println(colCount);
String fieldName="";//sql中的字段名或别名
Field field=null; //要包装的类中的属性对象
String prefixName="";//数据库字段的前缀名(映射类名)
Map<String,Object> refMap=new HashMap<String,Object>();//用来存放主类中引用类对象的属性名和对象
String key="";//用来标记refMap中的键
while(rs.next()){
List<T> claObjList=new ArrayList<T>();
for(Class cla:clazzs){//将要封装的实体类型实例化放入到List中,以便将rs中的值赋值给实例的属性
claObjList.add((T) cla.newInstance());
}
for(int j=0;j<clazzs.length;j++){
for(int i=1;i<=colCount;i++){
fieldName=md.getColumnName(i);
prefixName=fieldName.split("\\.")[0];//获得结果集中字段的前缀名
fieldName=fieldName.split("\\.")[1];//获得结果集中字段的名称
//System.out.println(clazzs[j].getSimpleName()+"==="+prefixName+"==="+fieldName+"---");
if(clazzs[j].getSimpleName().toLowerCase().equals(prefixName.toLowerCase())){
try {
//System.out.println(clazzs[j].getSimpleName());
field=clazzs[j].getDeclaredField(fieldName);//获得当前类中所有的字段对象
field.setAccessible(true);//设置Field的可访问性为true,否则私有属性不能访问
field.set(claObjList.get(j), convert(rs.getString(i),field.getType()));
//给参数数组对映的实例化对象的属性赋值
if(j>0) refMap.put(prefixName, claObjList.get(j));
//如果是第二个以后的对象,则放入到引用对象的Map中
} catch (Exception e) {
e.printStackTrace();
}
}
} }
Set<String> keySet=refMap.keySet();
Iterator<String> it=keySet.iterator();
while(it.hasNext()){
key=it.next();
try {
field=clazzs[0].getDeclaredField(key);//获得主类中外键对象的引用字段对象
field.setAccessible(true);//设置该字段可访问
field.set(claObjList.get(0), refMap.get(key));//将Map集合中该键对应的值赋值给该字段
} catch (Exception e) { }
}
list.add(claObjList.get(0));
}
} catch (SQLException e) {
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
closeAll(rs, ps, con);
}
return list;
}
/**
* 将传入的字符串参数转化成制定的数据类型,如果格式不匹配则返回null
*
* @param <T>
* @param param
* 要转换的参数字符串
* @param clas
* 转换的目标CLASS
* @return
*/
private <T extends Serializable> T convert(String param, Class clas) {
if (param == null || param == "" || clas == null)
return null;
String type = clas.getName();// 获得要转换的数据类型名称
//System.out.println(type);
if (type.equals("java.lang.String"))
{
//System.out.println("xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
return (T) param;
}
try {// 根据不同类型的属性,返回不同的结果,如果出现异常,则返回null
if (type.equals("java.util.Date")) {
return (T) new java.util.Date(java.sql.Timestamp.valueOf(param)
.getTime());
}
if (type.equals("java.sql.Date")) {
return (T) new java.sql.Date(java.sql.Timestamp.valueOf(param).getTime());
}
if (type.equals("java.sql.Timestamp")) {
return (T) java.sql.Timestamp.valueOf(param);
}
if (type.equals("java.lang.Char")) {
return (T) Character.valueOf(param.charAt(0));
}
if (type.equals("java.lang.Integer") || type.equals("int")) {
return (T) Integer.valueOf(param);
}
if (type.equals("java.lang.Double") || type.equals("double")) {
return (T) Double.valueOf(param);
}
if (type.equals("java.lang.Float") || type.equals("float")) {
return (T) Float.valueOf(param);
}
if (type.equals("java.lang.Byte") || type.equals("byte")) {
return (T) Byte.valueOf(param);
}
if (type.equals("java.lang.Short") || type.equals("short")) {
return (T) Short.valueOf(param);
}
if (type.equals("java.lang.Long") || type.equals("long")) {
return (T) Long.valueOf(param);
}
if (type.equals("java.lang.Boolean") || type.equals("boolean")) {
return (T) Boolean.valueOf(param);
}
} catch (Exception e) {
//e.printStackTrace();
}
return null;
}
/**
* 将sql语句中传入的地段名称转换为相应的set方法名
* @param fieldName 传入的sql语句的字段名称
* @return 返回set方法名称
*/
private String findSetMethodName(String fieldName) {
Character firstChar = fieldName.charAt(0);
firstChar = Character.toUpperCase(firstChar);
String methodName = "set"+firstChar + fieldName.substring(1);// 将首字母小写
return methodName;
}
public boolean updateTrans(String[] sql,List<Object[]> listParam) {
Connection con = null;
PreparedStatement pstmt = null;
try {
con = getConnection();
con.setAutoCommit(false);
for(int i=0;i<sql.length;i++){
pstmt = con.prepareStatement(sql[i]);
setParams(pstmt,listParam.get(i));
pstmt.executeUpdate();
}
con.commit();
return true;
} catch (Exception e) {
e.printStackTrace();
try {
con.rollback();
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
} finally {
closeAll(null,pstmt,con);
}
return false;
}
public int update(String sql,Object[] params) {
Connection con = null;
PreparedStatement pstmt = null;
try {
con = getConnection();
pstmt = con.prepareStatement(sql);
setParams(pstmt,params);
return pstmt.executeUpdate();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
closeAll(null,pstmt,con);
}
return -1;
} public int update(String sql,Object[] params,Connection con) {
PreparedStatement pstmt = null;
try {
con = getConnection();
pstmt = con.prepareStatement(sql);
setParams(pstmt,params);
return pstmt.executeUpdate();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
closeAll(null,pstmt,null);
}
return -1;
} /**
* 修改数据库信息的通用方法
* @param sql
* 一个sql语句
* @param params
* 参数数组
* @return
* 修改每条信息的主键,为int类型
*/
public int getKey(String sql,Object[] params) {
int id=0;
Connection conn=null;
PreparedStatement ps=null;
ResultSet rs=null;
try {
conn =getConnection();
ps = conn.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);
setParams(ps, params);
ps.executeUpdate();
rs = ps.getGeneratedKeys();
while(rs.next())
id=rs.getInt(1); } catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally{
closeAll(rs,ps,conn);
}
return id;
}
/**
* 修改数据库信息的通用方法
* @param sql
* 一个sql语句
* @param params
* 参数数组
* @param con
* 一个Connection对象
* @return
* 修改每条信息的主键,为int类型
*/
public int getKey(String sql,Object[] params,Connection con) {
int id=0;
PreparedStatement ps=null;
ResultSet rs=null;
try {
con = getConnection();
ps = con.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);
setParams(ps, params);
ps.executeUpdate();
rs = ps.getGeneratedKeys();
while(rs.next()){
id=rs.getInt(1);
} } catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally{
closeAll(rs,ps,null);
}
return id;
} /**
* 关闭连接对象
* @param rs
* @param ps
* @param con
*/
public void closeAll(ResultSet rs, Statement ps, Connection con) {
// TODO Auto-generated method stub
try {
if(rs != null){
rs.close();
rs = null;
}
if(ps != null){
ps.close();
ps = null;
}
if(con != null){
con.close();
con = null;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} }
/**
* 测试显示数据
* @param args
*/
public static void main(String[] args){
DaoFactory dao = new DaoFactory();
List li = dao.query("select * from rights", null);
System.out.println(li);
} }