「javaurl类型」java urldecode
本篇文章给大家谈谈javaurl类型，以及java urldecode对应的知识点，希望对各位有所帮助，不要忘了收藏本站喔。
本文目录一览：
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");
}
}
}
java中url和uir有什么区别
URI是URL的一个抽象,它不仅包括了统一资源定位符(URL),还包括了统一资源名(URN).大多数实际应用中使用的URI都是URL,但是许多规范和标准像XML都是用URI来定义的.在java1.4和更新的版本中, URI被java.net.URI 类所表示.这个类与java.net.URL 相比有如下3点重要的区别:
· URI 类只关心资源的标识和对URI的解析.它没有方法来检索它的URI所标识的资源。
· URI 类与URL 类相比，它更能适应相关的规范。
· 一个URI 对象能表示一个相对URI 。URL 类在存放之前，就已经对所有的URI进行了“绝对化”的处理。
看着是不是有点晕？
简单的这么理解吧，URL是统一资源定位符，URI是统一资源标识符，URL是URI的一种，但在Java里面不是一种类型，两个类也没有继承关系，但各自提供了toURL()和toURI()来相互转换，在需要的时候放上相应的类型。
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