包含jsp與java通訊的詞條

本文目錄一覽：

• 1、jsp，java串口通信的問題
• 2、jsp和Java後台數據如何交互
• 3、java開發的信息系統里，jsp與java文件是怎麼傳遞數據的啊？
• 4、spring 中如何實現jsp與java的交互
• 5、jsp與java文件怎麼傳遞數據？

jsp，java串口通信的問題

可以,使用comm,jar

class SerialExample {

public static void main(String[] args) {

//TO DO: Add your JAVA codes here

long curTime = System.currentTimeMillis();

long serialtime = 8000;

boolean state = true;

SerialBean SB = new SerialBean(2);//設置埠號2

String Msg = “AD 01 0D”;//發送命令

SB.Initialize(9600);//設置波率

SB.WritePort(Msg);//發送命令

/* for (int i = 5; i 10; i++) {

System.out.println( SB.ReadPort(3));//設置讀取個數

}

*/

String readdata = SB.ReadPort(“0D”,4000);//讀取以OD結束的數據,4000ms沒有數據就返回空

if (readdata.length() 0) { //System.out.println(readdata.length());//如果有讀到數據

System.out.println(readdata);//如果有讀到數據

}

while (readdata.length() 1 state) {//如果沒有讀到數據

readdata = SB.ReadPort(“0D”,4000);

System.out.println(readdata);

if (System.currentTimeMillis() – curTime serialtime) {

state = false;//設置讀取錯誤超時

}

System.out.println(“readdaa:” + state);

System.out.println(System.currentTimeMillis() – curTime);

}

if (!state) {

System.out.println(“數據讀取超時”);

}

SB.ClosePort();//關閉連接

}

}

public class SerialBuffer {

Convents cv = new Convents();

private String Content = “”;

private String CurrentMsg, TempContent;

private boolean available = false;

private int LengthNeeded = 1;

String str = “”;

byte b;

/**

*

* This function returns a string with a certain length from the incoming

* messages.

*

* @param Length The length of the string to be returned.

*

*/

public synchronized String GetMsg(int Length) {

LengthNeeded = Length;

long timeout=2000;

long curtime=System.currentTimeMillis();

notifyAll();

if (LengthNeeded Content.length()) {

available = false;

while (available == false) {

try {

if(System.currentTimeMillis()-curtimetimeout) wait();

} catch (InterruptedException e) {

}

}

}

CurrentMsg = Content.substring(0, LengthNeeded);

TempContent = Content.substring(LengthNeeded);

Content = TempContent;

LengthNeeded = 1;

notifyAll();

return CurrentMsg;

}

public synchronized String GetMsg(String endstring,long timeout) {

LengthNeeded =Content.indexOf(endstring);

notifyAll();

if (LengthNeeded 0) {

available = false;

while (available == false) {

try {

wait(timeout);

available=true;

} catch (InterruptedException e) {

}

}

return “”;

}

if (LengthNeeded 0) {

CurrentMsg = Content.substring(0, LengthNeeded+endstring.length());

TempContent = Content.substring(LengthNeeded+endstring.length());

Content = TempContent;

}

LengthNeeded = -1;

notifyAll();

return CurrentMsg;

}

public synchronized void PutChar(int c) {

Content = Content.concat(cv.byteToHexString(c));

if (LengthNeeded Content.length() Content.length() 0) {

available = true;

}

notifyAll();

}

}

/*

* To change this template, choose Tools | Templates

* and open the template in the editor.

*/

package common.serial;

/**

*

* @author Jason

*/

import java.io.*;

import java.util.*;

import javax.comm.*;

import common.code.Convents;

public class SerialBean {

Convents cv=new Convents();

String PortName = “”;

CommPortIdentifier portId = null;

SerialPort serialPort = null;

OutputStream out;

InputStream in;

SerialBuffer SB;

ReadSerial RT;

int rate=9600;

String endstring =””;

long timeout=2000;

public SerialBean(int PortID) {

PortName = “COM” + PortID;

}

public int Initialize(int rate) {

int InitSuccess = 1;

int InitFail = -1;

try {

portId = CommPortIdentifier.getPortIdentifier(PortName);

try {

serialPort = (SerialPort) portId.open(“Serial_Communication”, 2000);

} catch (PortInUseException e) {

return InitFail;

}

//Use InputStream in to read from the serial port, and OutputStream

//out to write to the serial port.

try {

in = serialPort.getInputStream();

out = serialPort.getOutputStream();

} catch (IOException e) {

return InitFail;

}

//Initialize the communication parameters to 9600, 8, 1, none.

try {

serialPort.setSerialPortParams(rate,

SerialPort.DATABITS_8,

SerialPort.STOPBITS_1,

SerialPort.PARITY_NONE);

} catch (UnsupportedCommOperationException e) {

return InitFail;

}

} catch (NoSuchPortException e) {

return InitFail;

}

SB = new SerialBuffer();

RT = new ReadSerial(SB, in);

RT.start();

return InitSuccess;

}

public String ReadPort(int Length) {

String Msg;

Msg = SB.GetMsg(Length);

return Msg;

}

public String ReadPort(String endstring,long timeout) {

String Msg;

Msg = SB.GetMsg(endstring,timeout);

return Msg;

}

public void WritePort(String Msg) {

try {

out.write(cv.hexStringToByte(Msg));

} catch (IOException e) {

}

}

public void ClosePort() {

serialPort.close();

}

}

package common.serial;

import java.io.*;

public class ReadSerial extends Thread {

private SerialBuffer ComBuffer;

private InputStream ComPort;

char[] ch;

public ReadSerial(SerialBuffer SB, InputStream Port) {

ComBuffer = SB;

ComPort = Port;

}

@Override

public void run() {

int c;

try {

while (true) {

c=ComPort.read();

ComBuffer.PutChar(c);

}

} catch (IOException e) {

}

}

}

/*

* To change this template, choose Tools | Templates

* and open the template in the editor.

*/

package common.serial;

/**

*

* @author Administrator

*/

public class PortOpreate {

private String sendtxt=””;

private String recivetxt=””;

private int comid = 1;

private int comrate = 9600;

private int timeout = 4000;

private long waittime = 13000;

private String endtxt = “0D”;

private boolean pstate=false;

private String massage=””;

public void PortOpreate(boolean hasreturn) {

long curTime = System.currentTimeMillis();

long serialtime = getWaittime();

boolean state = true;

int t=0;

SerialBean SB = new SerialBean(getComid());//設置埠號2

t=SB.Initialize(getComrate());//設置波率

if(t0){

SB.WritePort(getSendtxt());//發送命令

if (hasreturn) {

String readdata = SB.ReadPort(getEndtxt(), getTimeout());//讀取以OD結束的數據,4000ms沒有數據就返回空

if (readdata.length() 0) { //System.out.println(readdata.length());//如果有讀到數據

System.out.println(readdata);//如果有讀到數據

}

while (readdata.length() 1 state) {//如果沒有讀到數據

readdata = SB.ReadPort(getEndtxt(), getTimeout());

System.out.println(readdata);

if (System.currentTimeMillis() – curTime serialtime) {

state = false;//設置讀取錯誤超時

}

System.out.println(“readdaa:” + state);

System.out.println(System.currentTimeMillis() – curTime);

}

if (!state) {

System.out.println(“數據讀取超時”);

setMassage(“數據讀取超時”);

}

setRecivetxt(readdata);

setPstate(state);

}

SB.ClosePort();//關閉連接

}else{

System.out.println(“埠號出現錯誤”);

setMassage(“埠號出現錯誤”);

}

}

/**

* @return the sendtxt

*/

public String getSendtxt() {

return sendtxt;

}

/**

* @param sendtxt the sendtxt to set

*/

public void setSendtxt(String sendtxt) {

this.sendtxt = sendtxt;

}

/**

* @return the recivetxt

*/

public String getRecivetxt() {

return recivetxt;

}

/**

* @param recivetxt the recivetxt to set

*/

public void setRecivetxt(String recivetxt) {

this.recivetxt = recivetxt;

}

/**

* @return the comid

*/

public int getComid() {

return comid;

}

public void setComid(int comid) {

this.comid = comid;

}

public int getComrate() {

return comrate;

}

public void setComrate(int comrate) {

this.comrate = comrate;

}

public int getTimeout() {

return timeout;

}

public void setTimeout(int timeout) {

this.timeout = timeout;

}

public long getWaittime() {

return waittime;

}

public void setWaittime(long waittime) {

this.waittime = waittime;

}

public String getEndtxt() {

return endtxt;

}

public void setEndtxt(String endtxt) {

this.endtxt = endtxt;

}

public boolean isPstate() {

return pstate;

}

public void setPstate(boolean pstate) {

this.pstate = pstate;

}

public String getMassage() {

return massage;

}

public void setMassage(String massage) {

this.massage = massage;

}

}

package common.serial;

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

public class PortOperatorServlet extends HttpServlet {

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

response.setContentType(“text/html;charset=UTF-8”);

PrintWriter out = response.getWriter();

try {

long curTime = System.currentTimeMillis();

long serialtime = 8000;

boolean state = true;

String Msg = “AD 01 0D”;//發送命令

SerialBean SB = new SerialBean(10);//設置埠號2

SB.Initialize(9600);//設置波率

SB.WritePort(Msg);//發送命令

/* for (int i = 5; i 10; i++) {

System.out.println( SB.ReadPort(3));//設置讀取個數

}

*/

String readdata = SB.ReadPort(“0D”,4000);//讀取以OD結束的數據

if (readdata.length() 0) { //System.out.println(readdata.length());//如果有讀到數據

System.out.println(readdata);//如果有讀到數據

}

while (readdata.length() 1 state) {//如果沒有讀到數據

readdata = SB.ReadPort(“0D”,4000);

System.out.println(readdata);

out.println(readdata);

if (System.currentTimeMillis() – curTime serialtime) {

state = false;//設置讀取錯誤超時

}

System.out.println(“readdaa:” + state);

System.out.println(System.currentTimeMillis() – curTime);

}

if (!state) {

System.out.println(“數據讀取超時”);

out.println(“數據讀取超時”);

}

SB.ClosePort();//關閉連接

} finally {

out.close();

}

}

protected void doGet(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

processRequest(request, response);

}

protected void doPost(HttpServletRequest request, HttpServletResponse response)

throws ServletException, IOException {

processRequest(request, response);

}

public String getServletInfo() {

return “Short description”;

}

}

package common.code;

public final class Convents {

public final static char[] BToA = “0123456789abcdef”.toCharArray();

/**

* 把16進位字元串轉換成位元組數組A1 01 0D

* @param hex

* @return

*/

public byte[] hexStringToByte(String hex) {

String str[] = hex.split(” “);

int len = str.length;

byte[] result = new byte[len];

char[] achar = hex.toCharArray();

for (int i = 0; i len; i++) {

result[i] = (byte) (toByte(str[i].charAt(0)) * 16 + toByte(str[i].charAt(1)));

}

return result;

}

private static byte toByte(char c) {

byte b = (byte) (“0123456789ABCDEF”.indexOf(c));

return b;

}

/**

* 把位元組數組轉換成16進位字元串

* @param bArray

* @return

*/

public String byteToHexString(int b){

String st=””;

st=Integer.toHexString(b);

if (st.length() 2) {

st=”0″+Integer.toHexString(b).toUpperCase()+” “;

} else {

st=Integer.toHexString(b).toUpperCase()+” “;

}

return st;

}

public String bytesToHexString(byte[] bArray) {

StringBuffer sb = new StringBuffer(bArray.length);

String sTemp;

for (int i = 0; i bArray.length; i++) {

sTemp = Integer.toHexString(bArray[i]).toUpperCase();

}

return sb.toString();

}

}

jsp和Java後台數據如何交互

%

String path = request.getContextPath();

%

獲取jsp所在工程的名稱

var ids = new Array();

$.ajax({

type : “POST”,

contentType : ‘application/json’,

url : ‘%=path%/ui/product/havePsmPackage’,

data:JSON.stringify(ids),

async :false,

dataType : “json”,

success : function(data) {

},

error:function(){

}

});

1、前台如果傳的是一個集合，後台可以使用參數 @RequestBody ListString ids 來接收

2、如果前台是這種傳值方式 data:{“name”:name,”id”:id},

那後台可以通過創建一個欄位名稱對應的實體類來接收

或者使用String name = request.getParameter(“name”)的方式來接收

3、如果ajax選擇的GET方法，那後台方法的欄位名稱和url的入參名稱保持一致就能接收到數據了

4、window.location.href=”%=path%/ui/psmpackage/toPsmPackageList”;

這是跳轉到新頁面的方法

@RequestMapping(value = “/toPsmPackageList”)

public String toPsmPackageList(HttpServletRequest request) {

return “psmPackage/psmPackageList”;

}

這是後台的接受方式，返回的是對應jsp的文件夾和文件名

頁面跳轉的方法不需要@ResponseBody註解，而獲取返回值的方法則一定要加，不然獲取不到返回值

5、window.open(url); 可以在瀏覽器上新開一個頁面。對應的是window.close();

6、如何將數據帶到新增的頁面

第一：第一個頁面通過

window.location.href=”%=path%/ui/product/condition?lineCode=”+lineCode+”typeCode=”+typeCode;傳值

在新頁面可以通過var lineCode = ‘%=(String)request.getParameter(“lineCode”)%’這種方式來取值

第二：後台代碼這樣處理request.setAttribute(“product”, result);

input name=”id” type=”text” value=”${product.id}” /

${}來取值。

java開發的信息系統里，jsp與java文件是怎麼傳遞數據的啊？

jsp與java文件傳遞數據可以使用Servlet類來傳遞，jsp將數據存入到request對象中，Servlet類獲取這個request對象，並將數據取出。

示例代碼如下：

JSP代碼：%@ page language=”java” import=”java.util.*” pageEncoding=”UTF-8″%

!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”

html

  head

    titleDemo/title

  /head

  body

      form action=”/demoServlet” method=”post”

          input type=”text” name=”name”/

          input type=”submit” value=”提交”/

      /form

  /body

/html

Servlet代碼：

public class DemoServlet extends HttpServlet {

    public void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        String name = request.getParameter(“name”);//獲取jsp頁面輸入的參數

        System.out.println(name);

    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        doGet(request, response);

    }

}

表單提交之後，調用Servlet類的方法，通過request對象獲取jsp頁面傳入的參數值，實現數據的傳遞。

spring 中如何實現jsp與java的交互

spring中利用mvc框架就可以實現jsp和java交互了。

以下用spring mvc輸出hello world為例來說明：

一、項目依賴的jar包：

1.Spring框架依賴的jar包：

日誌：commons-logging-1.1.3.jar；

JSTL支持：jakarta-taglibs-standard-1.1.2中的jstl.jar和standard.jar；

2.Spring的jar包：

spring-framework-3.2.5.RELEASE/libs中的jar包（這裡為了方便我直接把全部都複製過去了）；

把以上的jar包全部複製到項目的WebContent/WEB-INF/lib目錄中。

二、在/WEB-INF中添加web.xml文件，文件內容如下：

?xml version=”1.0″ encoding=”UTF-8″?

web-app xmlns:xsi=”” xmlns=”” xmlns:web=”” xsi:schemaLocation=” ” id=”WebApp_ID” version=”3.0″

 display-nameSpringMVCLesson/display-name

   servlet

       servlet-nameSpringMVCLesson/servlet-name

       servlet-classorg.springframework.web.servlet.DispatcherServlet/servlet-class

       init-param

           param-namecontextConfigLocation/param-name

           param-valueclasspath:springservlet-config.xml/param-value

       /init-param

       load-on-startup1/load-on-startup!– load-on-startup必須放在最後 —

   /servlet

   !– Spring MVC配置文件結束 —

   servlet-mapping

       servlet-nameSpringMVCLesson/servlet-name

       url-pattern//url-pattern

   /servlet-mapping

/web-app

三、springservlet-config.xml文件配置：

在項目中新建一個resources的Source Folder文件夾，並添加springservlet-config.xml文件。

?xml version=”1.0″ encoding=”UTF-8″?

beans xmlns=””

 xmlns:xsi=””

 xmlns:p=””

 xmlns:context=””

 xmlns:util=””

 xmlns:mvc=””

 xsi:schemaLocation=”

 ”

   !– 默認的註解映射的支持 —  

   mvc:annotation-driven/

   !– 如果當前請求為「/」時，則轉發到「/helloworld/index」 —

   mvc:view-controller path=”/” view-name=”forward:/helloworld/index”/

   !– 靜態資源映射 —

   mvc:resources mapping=”/js/**” location=”/WEB-INF/js/” /

   mvc:resources mapping=”/css/**” location=”/WEB-INF/css/” /

   mvc:resources mapping=”/fonts/**” location=”/WEB-INF/fonts/” /

   mvc:resources mapping=”/plugins/**” location=”/WEB-INF/plugins/” /

   mvc:resources mapping=”images/**” location=”/WEB-INF/images/” /

   !– 當上面要訪問的靜態資源不包括在上面的配置中時，則根據此配置來訪問 —

   mvc:default-servlet-handler/

   !– 開啟controller註解支持 —

   !– use-default-filters=”false” 只掃描指定的註解 —

   context:component-scan base-package=”com.demo.web.controllers” use-default-filters=”false”

       context:include-filter type=”annotation” expression=”org.springframework.stereotype.Controller”/

   /context:component-scan

   !– 視圖解析器 —

   bean class=”org.springframework.web.servlet.view.InternalResourceViewResolver”

      property name=”viewClass” value=”org.springframework.web.servlet.view.JstlView”/

      property name=”contentType” value=”text/html”/        

      property name=”prefix” value=”/WEB-INF/views/”/

      property name=”suffix” value=”.jsp”/

   /bean

/beans

mvc:annotation-driven/ 開啟註解映射支持，它是為了簡化配置的縮寫形式，它相當於以下2個配置：

bean class=”org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping”/

bean class=”org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter”/

由於我們在web.xml文件裡面配置的是攔截所有的請求到該servlet，所以我們在這裡要對靜態資源文件映射作一下配置，否則請求這些資源文件會返回404：

!– 靜態資源映射 —

mvc:resources mapping=”/js/**” location=”/WEB-INF/js/” /

mvc:resources mapping=”/css/**” location=”/WEB-INF/css/” /

mvc:resources mapping=”/fonts/**” location=”/WEB-INF/fonts/” /

mvc:resources mapping=”/plugins/**” location=”/WEB-INF/plugins/” /

mvc:resources mapping=”images/**” location=”/WEB-INF/images/” /

!– 當上面要訪問的靜態資源不包括在上面的配置中時，則根據此配置來訪問 —

mvc:default-servlet-handler/

開啟Controller註解支持，並配置只掃描指定包下面的Controller：

context:component-scan base-package=”com.demo.web.controllers” use-default-filters=”false”

   context:include-filter type=”annotation” expression=”org.springframework.stereotype.Controller”/

/context:component-scan

配置視圖解析器，並指定視圖所在的文件夾：

bean class=”org.springframework.web.servlet.view.InternalResourceViewResolver”

  property name=”viewClass” value=”org.springframework.web.servlet.view.JstlView”/

  property name=”contentType” value=”text/html”/        

  property name=”prefix” value=”/WEB-INF/views/”/

  property name=”suffix” value=”.jsp”/

/bean

添加HelloWorldController，在項目中新建一個web的Source Folder文件夾，並在文件夾下面添加com.demo.web.controllers包，在包中添加一個HelloWorldController類，類中內容如下：

package com.demo.web.controllers;

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestMethod;

import org.springframework.web.servlet.ModelAndView;

@Controller

@RequestMapping(value = “/helloworld”)

public class HelloWorldController {

   @RequestMapping(value=”/index”, method = {RequestMethod.GET})

   public ModelAndView index(){

       ModelAndView modelAndView = new ModelAndView();  

       modelAndView.addObject(“message”, “Hello World!”);  

       modelAndView.setViewName(“index”);  

       return modelAndView;

   }

}

其中@Controller 註解把該class指定為controller，controller 上的@RequestMapping 註解的 value值指定該controller所映射的請求。

方法上的@RequestMapping 註解指定該方法為一個action，value 值指定該action所映射的請求，method 中的RequestMethod.GET指定該action只接受get請求。

ModelAndView 中的setViewName指定了該action所對應的視圖名稱，解析視圖時會在springservlet-config.xml文件指定的視圖文件夾中尋找對應的視圖。

添加視圖，在項目/WEB-INF文件夾下新建一個views文件夾，並在views中添加index.jsp視圖，視圖內容如下：

%@ page language=”java” contentType=”text/html; charset=UTF-8″

   pageEncoding=”UTF-8″%

!DOCTYPE html PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN” “”

html

head

meta http-equiv=”Content-Type” content=”text/html; charset=UTF-8″

titleInsert title here/title

/head

body

   ${message}

/body

/html

運行項目輸出結果：

jsp與java文件怎麼傳遞數據？

可以使用Servlet類來傳遞

返回一個RequestDispatcher對象

該對象的forward()方法用於轉發請求

RequestDispatcher getRequestDispatcher(String path)

例如:request.getRequestDispatcher(「url」),forward(request,response);

設置追加請求中所需的屬性參數

Void setAttribute(「屬性名」,」屬性值」)

例如:request,setAttribute(「username」,」administrator」);

用於獲取請求中攜帶的屬性參數

Object getAttribute(「屬性名」)

例如:String usernam=(String)request.getAttribute(「username」);

響應對象response方法:response.sendRedirect(「url」);

用於充定向一個新的URL地址

經常配合使用session會話對象進行所需屬性參數的傳遞

例如:session,setAttribute(「username」,」administrator」);

session.serAttribute(「password」,」123456」);

…

If()username!=null{

Out.println(「歡迎你:」+username.toString()

}

2.轉發和重定向的區別

分別從5個點進行劃分區別

(1)URl變化:轉發不會發生變化,重定向會改變地址欄的URL

(2)重新發出請求:轉發不會,從頭至尾只有一次請求,重定向會發起兩次請求

(3)是否攜帶請求:轉發會攜帶request相關信息,重定向不會攜帶,所以會丟失

(4)目標URl要求:轉發只能跳轉WEB項目下的目標文件,重定向可跳轉任意URL

(5)行為區別:轉發時伺服器端的行為,重定向時客戶端行為

3.四中常用的跳轉方式

(1)後台發起轉發請求

request.getRequestDispatcher(「index.jsp」).forward(request,response);

(2)後台發起重定向

Response.sendRedirect(「indec.jsp」);

!–3.jsp標籤跳轉 相當於前端的轉發–

jsp:forward page=」index.jsp」

jsp:param value=」admin」 name=」user name」

jsp:param value=」123456」 name=」password」

/jsp:forward

!–4.超鏈接跳轉 get請求方式跳轉頁面 類似於前段的重定向–

a href=」index.jsp?username=adminadminpassword=123456」跳轉index.jsp/a