「java创建url」Java创建线程
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本文目录一览：
- 1、用java怎么写URL接口
- 2、java建立url请求 服务器怎么写
- 3、java中如何实现URL类?
- 4、如何用java程序实现上传文件到指定的URL地址
- 5、java构造方法URL(URL urlobj,String urlSpecifier)是什么意思？
- 6、java 怎么使用远程 url 创建 file
用java怎么写URL接口
在java中，调用http请求接口，主要通过流的方式进行调用，示例接口如下：
/**
* 程序中访问http数据接口
*/
public String searchLoginService(String urlStr) {
/** 网络的url地址 */
URL url = null;
/** http连接 */
HttpURLConnection httpConn = null;
/**//** 输入流 */
BufferedReader in = null;
StringBuffer sb = new StringBuffer();
try{
url = new URL(urlStr);
in = new BufferedReader( new InputStreamReader(url.openStream(),"UTF-8") );
String str = null;
while((str = in.readLine()) != null) {
sb.append( str );
}
} catch (Exception ex) {
logger.error(ex.getMessage(), ex);
} finally{
try{
if(in!=null) {
in.close();
}
}catch(IOException ex) {
logger.error(ex.getMessage(), ex);
}
}
String result =sb.toString();
System.out.println(result);
return result;
}
java建立url请求 服务器怎么写
//get请求
public String get(String url){
HttpURLConnection conn = null;
BufferedReader rd = null ;
StringBuilder sb = new StringBuilder ();
String line = null ;
String response = null;
try {
conn = (HttpURLConnection) new URL(url).openConnection();
conn.setRequestMethod("GET");
conn.setDoInput(true);
//conn.setReadTimeout(20000);
//conn.setConnectTimeout(20000);
conn.setUseCaches(false);
conn.connect();
rd = new BufferedReader( new InputStreamReader(conn.getInputStream(), "UTF-8"));
while ((line = rd.readLine()) != null ) {
sb.append(line);
}
response = sb.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
if(rd != null){
rd.close();
}
if(conn != null){
conn.disconnect();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return response;
}
//post表单请求
public String post(String url, MapString, String form){
HttpURLConnection conn = null;
PrintWriter pw = null ;
BufferedReader rd = null ;
StringBuilder out = new StringBuilder();
StringBuilder sb = new StringBuilder();
String line = null ;
String response = null;
for (String key : form.keySet()) {
if(out.length()!=0){
out.append("");
}
out.append(key).append("=").append(form.get(key));
}
try {
conn = (HttpURLConnection) new URL(url).openConnection();
conn.setRequestMethod("POST");
conn.setDoOutput(true);
conn.setDoInput(true);
//conn.setReadTimeout(20000);
//conn.setConnectTimeout(20000);
conn.setUseCaches(false);
conn.connect();
pw = new PrintWriter(conn.getOutputStream());
pw.print(out.toString());
pw.flush();
rd = new BufferedReader( new InputStreamReader(conn.getInputStream(), "UTF-8"));
while ((line = rd.readLine()) != null ) {
sb.append(line);
}
response = sb.toString();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}finally{
try {
if(pw != null){
pw.close();
}
if(rd != null){
rd.close();
}
if(conn != null){
conn.disconnect();
}
} catch (IOException e) {
e.printStackTrace();
}
}
return response;
}
java中如何实现URL类?
import java.io.*;
import java.net.*;
public class URLTest
{
public static void main(String[] args)
{
try
{
URL url=new URL("");//创建资源类型
String protocol=url.getProtocol();//获取资源类型
String host=url.getHost();//获取域名
int port=url.getPort();//获取端口
String file=url.getFile();//获取路径
System.out.println("url地址的资源类型为："+protocol+"域名为："+host+"端口为:"+port+"路径为:"+file);
InputStream is=url.openStream();//获取页面信息流
BufferedReader bfr=new BufferedReader(new InputStreamReader(is));//封装成字符流
String len;
while((len=bfr.readLine())!=null)
{
System.out.println(len);
}
bfr.close();
is.close();
}
catch(MalformedURLException e)
{
System.out.println("创建URL对象发生异常");
}
catch(IOException e)
{
System.out.println("发生IO操作异常");
}
}
}
如何用java程序实现上传文件到指定的URL地址
参考代码如下：
import java.io.*;
/**
* 复制文件夹或文件夹
*/
public class CopyDirectory {
// 源文件夹
static String url1 = "f:/photos";
// 目标文件夹
static String url2 = "d:/tempPhotos";
public static void main(String args[]) throws IOException {
// 创建目标文件夹
(new File(url2)).mkdirs();
// 获取源文件夹当前下的文件或目录
File[] file = (new File(url1)).listFiles();
for (int i = 0; i file.length; i++) {
if (file[i].isFile()) {
// 复制文件
copyFile(file[i],new File(url2+file[i].getName()));
}
if (file[i].isDirectory()) {
// 复制目录
String sourceDir=url1+File.separator+file[i].getName();
String targetDir=url2+File.separator+file[i].getName();
copyDirectiory(sourceDir, targetDir);
}
}
}
// 复制文件
public static void copyFile(File sourceFile,File targetFile)
throws IOException{
// 新建文件输入流并对它进行缓冲
FileInputStream input = new FileInputStream(sourceFile);
BufferedInputStream inBuff=new BufferedInputStream(input);
// 新建文件输出流并对它进行缓冲
FileOutputStream output = new FileOutputStream(targetFile);
BufferedOutputStream outBuff=new BufferedOutputStream(output);
// 缓冲数组
byte[] b = new byte[1024 * 5];
int len;
while ((len =inBuff.read(b)) != -1) {
outBuff.write(b, 0, len);
}
// 刷新此缓冲的输出流
outBuff.flush();
//关闭流
inBuff.close();
outBuff.close();
output.close();
input.close();
}
// 复制文件夹
public static void copyDirectiory(String sourceDir, String targetDir)
throws IOException {
// 新建目标目录
(new File(targetDir)).mkdirs();
// 获取源文件夹当前下的文件或目录
File[] file = (new File(sourceDir)).listFiles();
for (int i = 0; i file.length; i++) {
if (file[i].isFile()) {
// 源文件
File sourceFile=file[i];
// 目标文件
File targetFile=new
File(new File(targetDir).getAbsolutePath()
+File.separator+file[i].getName());
copyFile(sourceFile,targetFile);
}
if (file[i].isDirectory()) {
// 准备复制的源文件夹
String dir1=sourceDir + "/" + file[i].getName();
// 准备复制的目标文件夹
String dir2=targetDir + "/"+ file[i].getName();
copyDirectiory(dir1, dir2);
}
}
}
}
java构造方法URL(URL urlobj,String urlSpecifier)是什么意思？
有参构造：
意思是你使用这个构造方法创建对象的时候需要给他传递两个参数。一个参数是URL类型（对象本身的类型），另一个字符串类型。列如 URL rul = new URL(new URL(),"str");
源码：
public URL(URL context, String spec) throws MalformedURLException {
this(context, spec, null);
}
两个参数的构造里调用了三个参数的构造。
具体三参数的构造可以参考源码
/**
* Creates a URL by parsing the given spec with the specified handler
* within a specified context. If the handler is null, the parsing
* occurs as with the two argument constructor.
*
* @param context the context in which to parse the specification.
* @param spec the {@code String} to parse as a URL.
* @param handler the stream handler for the URL.
* @exception MalformedURLException if no protocol is specified, or an
* unknown protocol is found, or {@code spec} is {@code null}.
* @exception SecurityException
* if a security manager exists and its
* {@code checkPermission} method doesn't allow
* specifying a stream handler.
* @see java.net.URL#URL(java.lang.String, java.lang.String,
* int, java.lang.String)
* @see java.net.URLStreamHandler
* @see java.net.URLStreamHandler#parseURL(java.net.URL,
* java.lang.String, int, int)
*/
public URL(URL context, String spec, URLStreamHandler handler)
throws MalformedURLException
{
String original = spec;
int i, limit, c;
int start = 0;
String newProtocol = null;
boolean aRef=false;
boolean isRelative = false;
// Check for permission to specify a handler
if (handler != null) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
checkSpecifyHandler(sm);
}
}
try {
limit = spec.length();
while ((limit 0) (spec.charAt(limit - 1) = ' ')) {
limit--; //eliminate trailing whitespace
}
while ((start limit) (spec.charAt(start) = ' ')) {
start++; // eliminate leading whitespace
}
if (spec.regionMatches(true, start, "url:", 0, 4)) {
start += 4;
}
if (start spec.length() spec.charAt(start) == '#') {
/* we're assuming this is a ref relative to the context URL.
* This means protocols cannot start w/ '#', but we must parse
* ref URL's like: "hello:there" w/ a ':' in them.
*/
aRef=true;
}
for (i = start ; !aRef (i limit)
((c = spec.charAt(i)) != '/') ; i++) {
if (c == ':') {
String s = spec.substring(start, i).toLowerCase();
if (isValidProtocol(s)) {
newProtocol = s;
start = i + 1;
}
break;
}
}
// Only use our context if the protocols match.
protocol = newProtocol;
if ((context != null) ((newProtocol == null) ||
newProtocol.equalsIgnoreCase(context.protocol))) {
// inherit the protocol handler from the context
// if not specified to the constructor
if (handler == null) {
handler = context.handler;
}
// If the context is a hierarchical URL scheme and the spec
// contains a matching scheme then maintain backwards
// compatibility and treat it as if the spec didn't contain
// the scheme; see 5.2.3 of RFC2396
if (context.path != null context.path.startsWith("/"))
newProtocol = null;
if (newProtocol == null) {
protocol = context.protocol;
authority = context.authority;
userInfo = context.userInfo;
host = context.host;
port = context.port;
file = context.file;
path = context.path;
isRelative = true;
}
}
if (protocol == null) {
throw new MalformedURLException("no protocol: "+original);
}
// Get the protocol handler if not specified or the protocol
// of the context could not be used
if (handler == null
(handler = getURLStreamHandler(protocol)) == null) {
throw new MalformedURLException("unknown protocol: "+protocol);
}
this.handler = handler;
i = spec.indexOf('#', start);
if (i = 0) {
ref = spec.substring(i + 1, limit);
limit = i;
}
/*
* Handle special case inheritance of query and fragment
* implied by RFC2396 section 5.2.2.
*/
if (isRelative start == limit) {
query = context.query;
if (ref == null) {
ref = context.ref;
}
}
handler.parseURL(this, spec, start, limit);
} catch(MalformedURLException e) {
throw e;
} catch(Exception e) {
MalformedURLException exception = new MalformedURLException(e.getMessage());
exception.initCause(e);
throw exception;
}
}
java 怎么使用远程 url 创建 file
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
/**
* @author lmq
*
*/
public class RemoteFile {
public static void main(String[] args) throws Exception {
File remoteFile = new File("//192.168.7.146/test/1.txt");// 192.168.7.146是对方机器IP，test是对方那个共享文件夹名字，如果没有共享是访问不到的
//远程文件其实主要是地址，地址弄对了就和本地文件没什么区别 ，windows里面//或者\\\\开头就表示这个文件是网络路径了其实这个地址就像我们再windows里面，点击开始
//然后点击运行，然后输入 \\192.168.7.146/test/1.txt访问远程文件一样的
BufferedReader br = new BufferedReader(new FileReader(remoteFile));
String str;
while ((str = br.readLine()) != null) {
System.out.println(str);
}
br.close();
}
}
如果是非共享文件 你只能通过url读取流来生成了
public void downUrlTxt(String fileName,String fileUrl,String downPath){
File savePath = new File(downPath);
if (!savePath.exists()) {
savePath.mkdir();
}
String[] urlname = fileUrl.split("/");
int len = urlname.length-1;
String uname = urlname[len];//获取文件名
try {
File file = new File(savePath+"/"+uname);//创建新文件
if(file!=null !file.exists()){
file.createNewFile();
}
OutputStream oputstream = new FileOutputStream(file);
URL url = new URL(fileUrl);
HttpURLConnection uc = (HttpURLConnection) url.openConnection();
uc.setDoInput(true);//设置是否要从 URL 连接读取数据,默认为true
uc.connect();
InputStream iputstream = uc.getInputStream();
System.out.println("file size is:"+uc.getContentLength());//打印文件长度
byte[] buffer = new byte[4*1024];
int byteRead = -1;
while((byteRead=(iputstream.read(buffer)))!= -1){
oputstream.write(buffer, 0, byteRead);
}
oputstream.flush();
iputstream.close();
oputstream.close();
} catch (Exception e) {
System.out.println("读取失败！");
e.printStackTrace();
}
System.out.println("生成文件路径："+downPath+fileName);
}
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发布于：2022-12-14，除非注明，否则均为原创文章，转载请注明出处。