linkimpl.java

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// Copyright 2005-2007 onetsoft.com
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package com.onetsoft.fastjsp;


import com.onetsoft.fastjsp.util.StringUtils;

import java.io.CharArrayWriter;
import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;
import java.util.BitSet;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;


/**
 * @author <a href="mailto:[e-mail]">hgw</a>
 */
class LinkImpl implements Link, Lifecycle {

    /**
     * URL构造原则：
     * 1.url第一个参数以'-'连接，其他均以查询参数构造。SEO 搜索规则下，'－'连字符不宜超过2个，因此只尝试静态化第一个参数。
     * 2.由于第一个参数针对 append() 的第一次调用，或 map 的 iterator 第一个 next() 值。Action 与页面“定位”没有直接关系，故均以查询参数构造。
     * ..a:因此在设置参数map时，须注意该参数应对“页面定位”有帮助，如：bbs的主题列表的"forumID"、用户信息的"uuserID"
     * 3.第一个参数不得包含 '/' 字符，若包含则以动态参数构造，此时意味者所有参数都是查询方式构造的。原因如下：
     * ..若参数字符name or value包含 '/' 或 '-，则该参数以动态url方式构造，原因：
     * ..a:'/':tomcat 6.x 会报错："HTTP 400 - 错误请求"
     * ..b:'-'或其他参数分隔连接。避免构造的性能损失
     * ..另：若第一个参数值是null，则该参数也会以“查询参数”方式构造。因为此时在静态化参数已经无意义。
     * 4.确实需要静态参数连接的，可直接调用 append(XXX,YYY,staic)
     * 5.map参数全部强制构造为查询参数
     * 6.其他参见{@link Link}说明
     */

    /* encode 静态变量 begin */
    static BitSet dontNeedEncoding;
    static final int caseDiff = ('a' - 'A');

    static {
        dontNeedEncoding = new BitSet(256);
        int i;
        for (i = 'a'; i <= 'z'; i++) {
            dontNeedEncoding.set(i);
        }
        for (i = 'A'; i <= 'Z'; i++) {
            dontNeedEncoding.set(i);
        }
        for (i = '0'; i <= '9'; i++) {
            dontNeedEncoding.set(i);
        }
        dontNeedEncoding.set(' '); /* encoding a space to a + is done
				    * in the encode() method */
        dontNeedEncoding.set('-');
        dontNeedEncoding.set('_');
        dontNeedEncoding.set('.');
        dontNeedEncoding.set('*');
    }
    /* encode 静态变量 end */


    final static String UCI = "uci";//unique component id
    final static char sp = '-';
    final static char sl = '/';         //静态参数若包含此字符，tomcat 6.x下会出现错误："HTTP 400 - 错误请求"
    final static String spx = "%2d";   // 参数值中'-'的url形式
    final static String qa = "&amp;"; //查询参数将，是否需要设置为"&amp;" 呢 ?


    private AbstractComponent co = null;
    private String pageName = null;

    private boolean append = false;  //是否'-'方式构造了静态化参数
    StringBuffer buf = new StringBuffer();

    private boolean staticParamAppend = false; //第一次静态url参数是否已经构造。注：第一次构造调用即为true(无论构造成功与否)，其他参数的"页面定位"意义不明确。

    private String anchor = null;
    private Map params = null;
    private int len = -1;     //保存静态参数url base 的长的，便于 Link 对象化操作（如：clone(),getURL(),toString()）后也能append()

    private StringBuffer qbuf = new StringBuffer(0);   //保存动态查询参数 e.g: a=XXX&b=YYY
    private int qBufLen = -1;    //保存动态查询参数url base 的长的，便于 Link 对象化操作（如：clone(),getURL(),toString()）后也能append()

    private CharArrayWriter charArrayWriter = new CharArrayWriter();


    public LinkImpl() {
    }

    public LinkImpl setComponent(AbstractComponent co) {
        this.co = co;
        return this;
    }

    public LinkImpl setPageName(String pageName) {
        this.pageName = pageName;
        return this;
    }

    public void init() {
        co.service.servicer.stateURL.encodeBeforeUrlBuild(this);
    }

    public void recycle() {
        co = null;
        pageName = null;
        append = false;
        staticParamAppend = false;
        anchor = null;
        if (params != null)
            params.clear();
        len = -1;
        charArrayWriter.reset();
        buf.delete(0, buf.length());
        qbuf.delete(0, qbuf.length());
        qBufLen = -1;
    }

    public Object clone() {
        LinkImpl o = new LinkImpl();
        o.co = co;
        o.pageName = pageName;
        o.append = append;

        o.buf = new StringBuffer(buf.toString());
        o.qbuf = new StringBuffer(qbuf.toString());

        o.staticParamAppend = staticParamAppend;
        o.anchor = anchor;
        if (params != null)
            o.params = new TreeMap(params);
        o.len = len;

        return o;
    }

    private void ensuedAppend() {
        if (append) {
            buf.append(sp);
        } else {
            buf.append(pageName).append('/');
            append = true;
        }
    }

    private void ensureBuffers() {
        if (len != -1) {
            buf.delete(len, buf.length());
            len = -1;
        }
        if (qBufLen != -1) {
            qbuf.delete(qBufLen, qbuf.length());
            qBufLen = -1;
        }
    }

    private Link appends(String param, String value, int paramPerfered) {
        ensureBuffers();
        if (value == null || value.length() == 0) {
            encodeURLParamQueryString(param, value);
            return this;
        }
        if (!(paramPerfered==Link.STATIC && encodeURLParamStatic(param, value))) {
            encodeURLParamQueryString(param, value);
        }
        return this;
    }

    private Link appendq(String param, String value, boolean forceQueryString, boolean resetBufer) {
        if (resetBufer)
            ensureBuffers();
        boolean b = true;
        if (!forceQueryString) {
            if (!staticParamAppend) {
                staticParamAppend = true;
                if (value != null && value.length() > 0) {
                    b = !encodeURLParamStatic(param, value);//静态参数添加失败则以动态参数添加
                }
            }
        }
        if (b) {
            encodeURLParamQueryString(param, value);
        }

        return this;
    }

    /* 编码静态URL */
    private boolean encodeURLParamStatic(String param, String value) {
        if (value.indexOf(sl) != -1) return false;

        ensuedAppend();
        buf.append(param).append(sp);
        encodeURLParam(buf, value, co.service.servicer.module.charset, true);

        return true;
    }

    /* 编码查询参数 */
    private void encodeURLParamQueryString(String param, String value) {
        /*存在特殊字符 */
        if (qbuf.length() > 0) {
            qbuf.append(qa);
        }

        qbuf.append(param).append('=');

        if (value == null || value.length() == 0) {
            qbuf.append(StringUtils.EMPTY);
        } else {
            encodeURLParam(qbuf, value, co.service.servicer.module.charset, false);
        }

        /* try {
        if (value != null)
            value = URLEncoder.encode(value, co.service.servicer.module.encoding);
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }
    if (value != null)
        qbuf.append(value);
    else
        qbuf.append(StringUtils.EMPTY);*/

    }


    public Link append(String param, String value) {
        ensureBuffers();
        return appendq(param, value, false, true);
    }

    public Link append(String param, String value, int paramPerfered) {
        return appends(param, value, paramPerfered);
    }

    public Link append(String param, long value) {