android java 如何判断一个url地址为有效url
2018-02-06 14:25
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我们在android 和java开发中可能会遇到一个问题,就是判断用户输入的url或者从网页或其他地方复制来的url是否为一个有效的url,下面是一些方法,供大家参考:
在没有encode的情况下可以使用下面方法
[java] view
plain copy
URI uriObj = new URI(url);
这个方法来进行判定,如果该方法抛出异常URISyntaxException,那么就说明这个url不是一个正确的url,不过当遇到一个url地址中包含字符串^的时候,也会抛出异常,可以这个含有^的链接却是一个有效的地址,比如百度中的某些地址,因此可以通过下面的代码进行改进:
[java] view
plain copy
URL urlObj = new URL(url);
URI uriObj = new URI(urlObj.getProtocol(), urlObj.getHost(), urlObj.getPath(), urlObj.getQuery(), null);
这两个方法分别会抛出MalformedURLException和URISyntaxException.
不过如果你想对一些schemes进行限制,可以加入以下代码:
[java] view
plain copy
private static final String acceptableSchemes[] = {
"http:",
"https:",
"file:"
};
private static boolean urlHasAcceptableScheme(String url) {
if (url == null) {
return false;
}
for (int i = 0; i < acceptableSchemes.length; i++) {
if (url.startsWith(acceptableSchemes[i])) {
return true;
}
}
return false;
}
private String isValidUrl(String incommingString) throws Exception{
String url = "";
URL urlObj = new URL(incommingString);
URI uriObj = new URI(urlObj.getProtocol(), urlObj.getHost(), urlObj.getPath(), urlObj.getQuery(), null);
String scheme = uriObj.getScheme();
if (!urlHasAcceptableScheme(incommingString)) {
if (scheme != null) {
throw new URISyntaxException("", "");
}
}
//此处需要对url进行赋值操作,例如需要加http://等
p; return url;
}
对于android开发,还可以以这样处理:
[java] view
plain copy
import android.util.Patterns;//android包下的
if (Patterns.WEB_URL.matcher(searchContent).matches()) {
//符合标准
} else{
//不符合标准
}
接下来提供一个完整的封装类,不但提供了对url的校验,还对url的大部分信息进行了封装操作,代码如下:
[java] view
plain copy
package 随便写;
import static android.util.Patterns.GOOD_IRI_CHAR;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class WebAddress {
private String mScheme;
private String mHost;
private int mPort;
private String mPath;
private String mAuthInfo;
static final int MATCH_GROUP_SCHEME = 1;
static final int MATCH_GROUP_AUTHORITY = 2;
static final int MATCH_GROUP_HOST = 3;
static final int MATCH_GROUP_PORT = 4;
static final int MATCH_GROUP_PATH = 5;
/* ENRICO: imported the ParseExeption here */
public static class ParseException extends RuntimeException {
public String response;
ParseException(String response) {
this.response = response;
}
}
//根据正则表达式进行判断
static Pattern sAddressPattern = Pattern.compile(
/* scheme */ "(?:(http|https|file)\\:\\/\\/)?" +
/* authority */ "(?:([-A-Za-z0-9$_.+!*'(),;?&=]+(?:\\:[-A-Za-z0-9$_.+!*'(),;?&=]+)?)@)?" +
/* host */ "([" + GOOD_IRI_CHAR + "%_-][" + GOOD_IRI_CHAR + "%_\\.-]*|\\[[0-9a-fA-F:\\.]+\\])?" +
/* port */ "(?:\\:([0-9]*))?" +
/* path */ "(\\/?[^#]*)?" +
/* anchor */ ".*", Pattern.CASE_INSENSITIVE);
/** parses given uriString. */
//用法:将需要判断的url传入,new WebAddress(address) 如果抛出异常,则会出现问题
public WebAddress(String address) throws ParseException {
if (address == null) {
throw new NullPointerException();
}
// android.util.Log.d(LOGTAG, "WebAddress: " + address);
mScheme = "";
mHost = "";
mPort = -1;
mPath = "/";
mAuthInfo = "";
Matcher m = sAddressPattern.matcher(address);
String t;
if (m.matches()) {
t = m.group(MATCH_GROUP_SCHEME);
if (t != null) mScheme = t.toLowerCase(Locale.getDefault());
t = m.group(MATCH_GROUP_AUTHORITY);
if (t != null) mAuthInfo = t;
t = m.group(MATCH_GROUP_HOST);
if (t != null) mHost = t;
t = m.group(MATCH_GROUP_PORT);
if (t != null && t.length() > 0) {
// The ':' character is not returned by the regex.
try {
mPort = Integer.parseInt(t);
} catch (NumberFormatException ex) {
throw new ParseException("Bad port");
}
}
t = m.group(MATCH_GROUP_PATH);
if (t != null && t.length() > 0) {
/* handle busted myspace frontpage redirect with
missing initial "/" */
if (t.charAt(0) == '/') {
mPath = t;
} else {
mPath = "/" + t;
}
}
} else {
// nothing found... outa here
throw new ParseException("Bad address");
}
/* Get port from scheme or scheme from port, if necessary and
possible */
if (mPort == 443 && mScheme.equals("")) {
mScheme = "https";
} else if (mPort == -1) {
if (mScheme.equals("https"))
mPort = 443;
else
mPort = 80; // default
}
if (mScheme.equals("")) mScheme = "http";
}
@Override
public String toString() {
String port = "";
if ((mPort != 443 && mScheme.equals("https")) ||
(mPort != 80 && mScheme.equals("http"))) {
port = ":" + Integer.toString(mPort);
}
String authInfo = "";
if (mAuthInfo.length() > 0) {
authInfo = mAuthInfo + "@";
}
return mScheme + "://" + authInfo + mHost + port + mPath;
}
public void setScheme(String scheme) {
mScheme = scheme;
}
public String getScheme() {
return mScheme;
}
public void setHost(String host) {
mHost = host;
}
public String getHost() {
return mHost;
}
public void setPort(int port) {
mPort = port;
}
public int getPort() {
return mPort;
}
public void setPath(String path) {
mPath = path;
}
public String getPath() {
return mPath;
}
public void setAuthInfo(String authInfo) {
mAuthInfo = authInfo;
}
public String getAuthInfo() {
return mAuthInfo;
}
}
在没有encode的情况下可以使用下面方法
[java] view
plain copy
URI uriObj = new URI(url);
这个方法来进行判定,如果该方法抛出异常URISyntaxException,那么就说明这个url不是一个正确的url,不过当遇到一个url地址中包含字符串^的时候,也会抛出异常,可以这个含有^的链接却是一个有效的地址,比如百度中的某些地址,因此可以通过下面的代码进行改进:
[java] view
plain copy
URL urlObj = new URL(url);
URI uriObj = new URI(urlObj.getProtocol(), urlObj.getHost(), urlObj.getPath(), urlObj.getQuery(), null);
这两个方法分别会抛出MalformedURLException和URISyntaxException.
不过如果你想对一些schemes进行限制,可以加入以下代码:
[java] view
plain copy
private static final String acceptableSchemes[] = {
"http:",
"https:",
"file:"
};
private static boolean urlHasAcceptableScheme(String url) {
if (url == null) {
return false;
}
for (int i = 0; i < acceptableSchemes.length; i++) {
if (url.startsWith(acceptableSchemes[i])) {
return true;
}
}
return false;
}
private String isValidUrl(String incommingString) throws Exception{
String url = "";
URL urlObj = new URL(incommingString);
URI uriObj = new URI(urlObj.getProtocol(), urlObj.getHost(), urlObj.getPath(), urlObj.getQuery(), null);
String scheme = uriObj.getScheme();
if (!urlHasAcceptableScheme(incommingString)) {
if (scheme != null) {
throw new URISyntaxException("", "");
}
}
//此处需要对url进行赋值操作,例如需要加http://等
p; return url;
}
对于android开发,还可以以这样处理:
[java] view
plain copy
import android.util.Patterns;//android包下的
if (Patterns.WEB_URL.matcher(searchContent).matches()) {
//符合标准
} else{
//不符合标准
}
接下来提供一个完整的封装类,不但提供了对url的校验,还对url的大部分信息进行了封装操作,代码如下:
[java] view
plain copy
package 随便写;
import static android.util.Patterns.GOOD_IRI_CHAR;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class WebAddress {
private String mScheme;
private String mHost;
private int mPort;
private String mPath;
private String mAuthInfo;
static final int MATCH_GROUP_SCHEME = 1;
static final int MATCH_GROUP_AUTHORITY = 2;
static final int MATCH_GROUP_HOST = 3;
static final int MATCH_GROUP_PORT = 4;
static final int MATCH_GROUP_PATH = 5;
/* ENRICO: imported the ParseExeption here */
public static class ParseException extends RuntimeException {
public String response;
ParseException(String response) {
this.response = response;
}
}
//根据正则表达式进行判断
static Pattern sAddressPattern = Pattern.compile(
/* scheme */ "(?:(http|https|file)\\:\\/\\/)?" +
/* authority */ "(?:([-A-Za-z0-9$_.+!*'(),;?&=]+(?:\\:[-A-Za-z0-9$_.+!*'(),;?&=]+)?)@)?" +
/* host */ "([" + GOOD_IRI_CHAR + "%_-][" + GOOD_IRI_CHAR + "%_\\.-]*|\\[[0-9a-fA-F:\\.]+\\])?" +
/* port */ "(?:\\:([0-9]*))?" +
/* path */ "(\\/?[^#]*)?" +
/* anchor */ ".*", Pattern.CASE_INSENSITIVE);
/** parses given uriString. */
//用法:将需要判断的url传入,new WebAddress(address) 如果抛出异常,则会出现问题
public WebAddress(String address) throws ParseException {
if (address == null) {
throw new NullPointerException();
}
// android.util.Log.d(LOGTAG, "WebAddress: " + address);
mScheme = "";
mHost = "";
mPort = -1;
mPath = "/";
mAuthInfo = "";
Matcher m = sAddressPattern.matcher(address);
String t;
if (m.matches()) {
t = m.group(MATCH_GROUP_SCHEME);
if (t != null) mScheme = t.toLowerCase(Locale.getDefault());
t = m.group(MATCH_GROUP_AUTHORITY);
if (t != null) mAuthInfo = t;
t = m.group(MATCH_GROUP_HOST);
if (t != null) mHost = t;
t = m.group(MATCH_GROUP_PORT);
if (t != null && t.length() > 0) {
// The ':' character is not returned by the regex.
try {
mPort = Integer.parseInt(t);
} catch (NumberFormatException ex) {
throw new ParseException("Bad port");
}
}
t = m.group(MATCH_GROUP_PATH);
if (t != null && t.length() > 0) {
/* handle busted myspace frontpage redirect with
missing initial "/" */
if (t.charAt(0) == '/') {
mPath = t;
} else {
mPath = "/" + t;
}
}
} else {
// nothing found... outa here
throw new ParseException("Bad address");
}
/* Get port from scheme or scheme from port, if necessary and
possible */
if (mPort == 443 && mScheme.equals("")) {
mScheme = "https";
} else if (mPort == -1) {
if (mScheme.equals("https"))
mPort = 443;
else
mPort = 80; // default
}
if (mScheme.equals("")) mScheme = "http";
}
@Override
public String toString() {
String port = "";
if ((mPort != 443 && mScheme.equals("https")) ||
(mPort != 80 && mScheme.equals("http"))) {
port = ":" + Integer.toString(mPort);
}
String authInfo = "";
if (mAuthInfo.length() > 0) {
authInfo = mAuthInfo + "@";
}
return mScheme + "://" + authInfo + mHost + port + mPath;
}
public void setScheme(String scheme) {
mScheme = scheme;
}
public String getScheme() {
return mScheme;
}
public void setHost(String host) {
mHost = host;
}
public String getHost() {
return mHost;
}
public void setPort(int port) {
mPort = port;
}
public int getPort() {
return mPort;
}
public void setPath(String path) {
mPath = path;
}
public String getPath() {
return mPath;
}
public void setAuthInfo(String authInfo) {
mAuthInfo = authInfo;
}
public String getAuthInfo() {
return mAuthInfo;
}
}
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