该类用于生成一个可用的URL，方便URL的生成和管理。
/**
* 构造的URL
* @author Alvin
*/
final public class UrlBuilder {
// 协议名称
private String scheme;
// 服务器名称
private String serverName;
// 端口号
private int serverPort;
// 上下文名称
private String[] paths;
// 参数集合
private Map<String, Object> parameters;
// 地址缓冲
private String urlBuffer = null;
// 路径缓冲
private String pathBuffer = null;
// 参数缓冲
private String parametersBuffer = null;
/**
* 构造器
*/
public UrlBuilder(String scheme, String serverName, int serverPort, String[] paths) {
if (paths != null) {
for (int i = 0; i < paths.length; i++) {
paths[i] = trimSeparator(paths[i]);
}
}
this.scheme = scheme;
this.serverName = serverName;
this.serverPort = serverPort;
this.paths = paths;
}
/**
* 构造器
*/
public UrlBuilder(String serverName, int serverPort, String[] paths) {
this("http", serverName, serverPort, paths);
}
/**
* 构造器
*/
public UrlBuilder(String serverName, int serverPort) {
this(serverName, serverPort, null);
}
/**
* 构造器
*/
public UrlBuilder(String serverName) {
this(serverName, 80, null);
}
/**
* 去除字符串前后的 /
*/
private static String trimSeparator(String path) {
boolean b1 = path.startsWith("/"), b2 = path.endsWith("/");
if (b1 && b2) {
path = path.substring(1, path.length() - 1);
} else if (b1) {
path = path.substring(1);
} else if (b2) {
path = path.substring(0, path.length() - 1);
}
return path;
}
/**
* 添加一个目录
*/
public void addPath(String path) {
path = trimSeparator(path);
if (path.isEmpty() == false) {
pathBuffer = null;
urlBuffer = null;
if (paths == null) {
paths = new String[] { path };
} else {
paths = Arrays.copyOf(paths, paths.length + 1);
paths[paths.length - 1] = path;
}
}
}
/**
* 添加若干目录
*/
public void addPath(String...paths) {
List<String> pathList = new ArrayList<>();
for (String path : paths) {
path = trimSeparator(path);
if (path.isEmpty() == false) {
pathList.add(path);
}
}
if (pathList.isEmpty() == false) {
pathBuffer = null;
urlBuffer = null;
if (this.paths == null) {
this.paths = pathList.toArray(new String[pathList.size()]);
} else {
int len = this.paths.length;
this.paths = Arrays.copyOf(this.paths, len + pathList.size());
for (int i = 0; i < pathList.size(); i++) {
this.paths[len + i] = pathList.get(i);
}
}
}
}
/**
* 删除目录
*/
public String removePath(int index) {
String value = paths[index];
String[] newArray = new String[paths.length - 1];
System.arraycopy(paths, 0, newArray, 0, index);
System.arraycopy(paths, index + 1, newArray, index, newArray.length - index);
paths = newArray;
urlBuffer = null;
pathBuffer = null;
return value;
}
/**
* 转为字符串
*/
public String toString(String encoding) {
if (urlBuffer == null) {
StringBuilder b = new StringBuilder(scheme);
b.append("://");
b.append(serverName);
b.append(serverPort == 80 ? "" : ":" + serverPort);
String path = getPath();
if (path.isEmpty() == false) {
b.append("/" + path);
}
String paramString = getParamString(encoding);
if (paramString.isEmpty() == false) {
b.append("?");
b.append(paramString);
}
urlBuffer = b.toString();
}
return urlBuffer;
}
@Override
public String toString() {
return toString("UTF-8");
}
/**
* 添加一个参数
*/
public void addParameter(String name, Object value) {
if (parameters == null) {
parameters = new LinkedHashMap<>();
}
parametersBuffer = null;
parameters.put(name, value);
}
/**
* 删除一个参数
*/
public Object removeParameter(String name) {
if (parameters == null) {
return null;
}
parametersBuffer = null;
return parameters.remove(name);
}
/**
* 获取一个参数
*/
public Object getParameter(String name) {
if (parameters == null) {
return null;
}
return parameters.get(name);
}
public void setScheme(String scheme) {
this.scheme = scheme;
urlBuffer = null;
}
public String getScheme() {
return scheme;
}
public void setServerName(String serverName) {
this.serverName = serverName;
urlBuffer = null;
}
public String getServerName() {
return serverName;
}
public void setServerPort(int serverPort) {
this.serverPort = serverPort;
urlBuffer = null;
}
public int getServerPort() {
return serverPort;
}
public String getPath(int index) {
return paths[index];
}
public String getPath() {
if (paths == null) {
return "";
}
if (pathBuffer == null) {
StringBuilder s = new StringBuilder();
for (String path : paths) {
if (s.length() > 0) {
s.append("/");
}
s.append(path);
}
pathBuffer = s.toString();
}
return pathBuffer;
}
public String getParamString(String encoding) {
if (parametersBuffer == null) {
parametersBuffer = makeParameters(parameters, encoding);
}
return parametersBuffer;
}
public String getParamString() {
return getParamString("UTF-8");
}
/**
* 解析URL
*/
public static UrlBuilder parse(String url, String urlEncoding) {
String schema, serverName, path = null, queryString = null;
int pos, pos2, port;
pos = url.indexOf("://");
if (pos < 0) {
schema = "http";
pos = 0;
} else {
schema = url.substring(0, pos).trim();
if (schema.isEmpty()) {
throw new IllegalArgumentException(url);
}
pos += 3;
}
pos2 = url.indexOf("/", pos);
if (pos2 < 0) {
serverName = url.substring(pos);
} else {
serverName = url.substring(pos, pos2).trim();
}
pos = pos2 + 1;
if (serverName.isEmpty()) {
throw new IllegalArgumentException(url);
}
pos2 = serverName.lastIndexOf(":");
if (pos2 < 0) {
port = 80;
} else {
port = Integer.parseInt(serverName.substring(pos2 + 1));
serverName = serverName.substring(0, pos2);
}
if (pos > 0) {
pos2 = url.indexOf("?", pos);
if (pos2 < 0) {
path = url.substring(pos);
} else {
path = url.substring(pos, pos2);
pos = pos2 + 1;
queryString = url.substring(pos);
}
}
UrlBuilder builder = new UrlBuilder(schema, serverName, port, path == null ? null : path.split("/"));
if (queryString != null) {
String[] qs = queryString.split("&");
if (qs != null) {
builder.parameters = new LinkedHashMap<>();
for (String q : qs) {
String[] nv = q.split("=", 2);
if (nv != null) {
try {
builder.parameters.put(nv[0], nv.length > 1 ? URLDecoder.decode(nv[1], urlEncoding) : "");
} catch (UnsupportedEncodingException e) {
throw new IllegalArgumentException(url);
}
}
}
}
}
return builder;
}
/**
* 解析URL
*/
public static UrlBuilder parse(String url) {
return parse(url, "UTF-8");
}
/**
* 产生参数字符串
*/
public static String makeParameters(Map<String, Object> parameters, String encoding) {
if (parameters == null || parameters.isEmpty()) {
return "";
}
StringBuilder s = new StringBuilder();
for (Entry<String, Object> e : parameters.entrySet()) {
if (s.length() > 0) {
s.append("&");
}
s.append(e.getKey());
s.append("=");
try {
s.append(e.getValue() == null ? "" : URLEncoder.encode(String.valueOf(e.getValue()), encoding));
} catch (UnsupportedEncodingException e1) {
throw new IllegalArgumentException(encoding);
}
}
return s.toString();
}
/**
* 产生参数字符串
*/
public static String makeParameters(Map<String, Object> parameters) {
return makeParameters(parameters, "UTF-8");
}
/**
* 连接两个地址
*/
public static String combinUrl(String url1, String url2) {
boolean b1 = url1.endsWith("/"), b2 = url2.startsWith("/");
if (b1 && b2) {
return url1 + url2.substring(1);
}
if (b1 || b2) {
return url1 + url2;
}
return url1 + "/" + url2;
}
}@Test
public void test() {
UrlBuilder builder = new UrlBuilder("localhost", 8080);
builder.addPath("xxx");
System.out.println(builder.toString());
builder.addPath("aaa", "bbb");
System.out.println(builder.toString());
builder.removePath(1);
System.out.println(builder.toString());
builder.addParameter("id", 100);
System.out.println(builder.toString());
builder.addParameter("name", "小李");
System.out.println(builder.toString());
builder.removeParameter("id");
System.out.println(builder.toString());
builder = UrlBuilder.parse("http://www.baidu.com:80/test/a.jsp?id=1");
System.out.println(builder);
}原文地址：http://blog.csdn.net/mousebaby808/article/details/37657569
