分頁處理類

java 代碼

package com.dz.tools;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

/**
 * 用於WEB的分頁類(基於ORACLE). 注意:當字段中有","號時,請用"#"號代替 例如:_columnList =
 * "id,to_char('2007-08-05','yyyy-mm-dd')"中
 * to_char('2007-08-05','yyyy-mm-dd')中的","號改爲"#",應寫爲: _columnList =
 * "id,to_char('2007-08-05'#'yyyy-mm-dd')" <br>
 * <br>
 *
 * @author dz
 * @version 版本號 1.00
 */
public class Page {

    private ArrayList list = new ArrayList();// 返回數據集.

    private int tCount = 0;// 總記錄數.

    private int tPages = 0;// 總頁數.

    private int cPage = 0;// 當前頁.

    private int cMinPage = 0;// 當前最小頁,用於<<.

    private int cMaxPage = 0;// 當前最大頁,用於>>.

    private int offset = 0;// 本頁最小記錄號.

    private int below = 0;// 本頁最大記錄號.

    private String first = "";// 第一頁.

    private String prev = "";// 上一頁.

    private String next = "";// 下一頁.

    private String last = "";// 最後一頁.

    private int specify = 0;// 指定顯示頁.

    private ArrayList pageList = new ArrayList();// 頁列表

    private int pageListCount = 0;// 所列頁總頁

    private int maxLine = 0;// 每頁最大顯示數.

    private String dataSourceName = "";// 數據源名.

    private String tableName = "";// 表名.

    private String columnList = "";// 字段列表.

    private String findCondition = "";// 查詢條件.

    private String pageQuery = "";// 頁面參數.

    /**
     * 該類的構造函數，無參數.
     *
     */
    public Page() {
    }

    /**
     * 設置數據源名.
     *
     * @param dataSourceName
     *            數據庫名
     */
    public void setDataSourceName(String dataSourceName) {
        this.dataSourceName = dataSourceName;
    }

    /**
     * 設置表名.
     *
     * @param tableName
     *            表名
     */
    public void setTableName(String tableName) {
        this.tableName = tableName;
    }

    /**
     * 設置字段列表.
     *
     * @param columnList
     *            字段列表
     */
    public void setColumnList(String columnList) {
        this.columnList = columnList;
    }

    /**
     * 設置字段列表.
     *
     * @param columnList[]
     *            字段列表
     */
    public void setColumnList(String[] columnList) {
        for (int i = 0; i < columnList.length; i++)
            if (i == columnList.length - 1)
                this.columnList += columnList[i];
            else
                this.columnList += columnList[i] + ",";
    }

    /**
     * 設置查詢條件
     *
     * @param findCondition
     *            查詢條件
     */
    public void setFindCondition(String findCondition) {
        this.findCondition = findCondition;
    }

    /**
     * 設置頁面傳遞參數，如有多個參數要傳遞，可多次調用.
     *
     * @param key
     *            參數名
     * @param value
     *            參數值
     */
    public void setPageQuery(String key, String value) {
        this.pageQuery += key + "=" + value + "&";
    }

    /**
     * 取頁面參數.
     *
     * @return 頁面參數
     */
    public String getPageQuery() {
        return pageQuery;
    }

    /**
     * 設置每頁最大顯示數
     *
     * @param maxLine
     *            每頁最大顯示數
     */
    public void setMaxLine(int maxLine) {
        this.maxLine = maxLine;
    }

    /**
     * 取總頁數.
     *
     * @return 總頁數
     */
    public int getTPages() {
        return tPages;
    }

    /**
     * 取當前頁.
     *
     * @return 當前頁
     */
    public int getCPage() {
        return cPage;
    }

    public String getcPage() {
        return cPage + "";
    }

    /**
     * 取第一頁.
     *
     * @return 第一頁
     */
    public String getFirst() {
        return first;
    }

    /**
     * 取上一頁.
     *
     * @return 上一頁
     */
    public String getPrev() {
        return prev;
    }

    /**
     * 取下一頁.
     *
     * @return 下一頁
     */
    public String getNext() {
        return next;
    }

    /**
     * 取最後一頁.
     *
     * @return 最後一頁
     */
    public String getLast() {
        return last;
    }

    /**
     * 取總記錄數.
     *
     * @return 總記錄數
     */
    public int getTCount() {
        return tCount;
    }

    public void setSpecify(int specify) {
        this.specify = specify;
    }

    public int getSpecify() {
        return specify;
    }

    /**
     * 生成頁列表. changeCatalog()之後調用
     *
     * @param current
     * @param csum
     * @return
     */
    private void setPageList() {

        int start = 1;

        if (cPage > pageListCount)
            if (cPage % pageListCount == 0)
                start = pageListCount
                        * ((int) Math.ceil(cPage / pageListCount) - 1) + 1;
            else
                start = pageListCount * (int) Math.ceil(cPage / pageListCount)
                        + 1;

        cMinPage = start - 1;
        int end = start + pageListCount;
        cMaxPage = end;
        if (end > tPages) {
            end = tPages;
            cMaxPage = 0;
        }

        for (int i = 0; i < pageListCount; i++) {
            if (start <= tPages) {
                pageList.add(new Integer(start));
                start++;
            }
        }

    }

    public ArrayList getPageList() {
        return pageList;
    }

    public void setPageListCount(int pageListCount) {
        this.pageListCount = pageListCount;
    }

    public int getCMaxPage() {
        return cMaxPage;
    }

    public int getCMinPage() {
        return cMinPage;
    }

    /**
     * 取記錄集.
     *
     * @return 記錄集
     */
    public ArrayList getList() {
        return list;
    }

    /**
     * 生成本頁參數. 在query()中獲取總記錄數後，執行SQL之前調用.
     */
    private void changeCatalog() {
        // 總頁數
        tPages = (int) Math.ceil((double) tCount / maxLine);

        // 當前頁
        if (specify == 0) {
            specify = 1;
        }
        if (specify > tPages) {
            specify = tPages;
        }

        // 本頁最小記錄號
        offset = (specify - 1) * maxLine + 1;

        // 本頁最大記錄號
        below = specify * maxLine;

        // 當前頁
        cPage = specify;

        // 首頁參數
        if (specify > 1)
            first = "?page=1&" + pageQuery;
        else
            first = "";
        // 上頁參數
        if (specify > 1)
            prev = "?page=" + (specify - 1) + "&" + pageQuery;
        else
            prev = "";
        // 下頁參數
        if (specify < tPages)
            next = "?page=" + (specify + 1) + "&" + pageQuery;
        else
            next = "";
        // 未頁參數
        if (specify < tPages)
            last = "?page=" + tPages + "&" + pageQuery;
        else
            last = "";
    }

    /**
     * 主操作類(使用page). 請在setXXX()之後，getXXX()方法之前調用
     *
     * @throws SQLException
     */
    public void query() throws SQLException {
        // 取數據庫連接
        Connection conn = Database.getConnection(dataSourceName);
        if (conn == null)
            throw new SQLException("獲取數據庫連接錯誤");
        Statement stmt = null;
        ResultSet rs = null;
        try {
            String sql = "SELECT count(*) FROM " + tableName + " "
                    + findCondition;
            stmt = conn.createStatement();
            rs = stmt.executeQuery(sql);
            while (rs.next())
                tCount = rs.getInt(1);// 總記錄數
            changeCatalog();
            //System.out.println(tCount);
            setPageList();
            // 設置查詢語句
            sql = "SELECT " + columnList.replaceAll("#", ",") + " FROM "
                    + tableName + " " + findCondition;
            sql = "SELECT rownum r1,t.* FROM (" + sql + ") t";
            sql = "SELECT r.* FROM (" + sql + ") r WHERE r1 BETWEEN " + offset
                    + " AND " + below;
            // System.out.println(specify);
            //System.out.println(sql);

            // 取記錄
            String[] _row = columnList.split(",");
            int _rownum = _row.length;
            rs = stmt.executeQuery(sql);
            while (rs.next()) {
                String[] _temp = new String[_rownum];
                for (int i = 0; i < _rownum; i++) {
                    _temp[i] = rs.getString(i + 2);
                    // System.out.println(_temp[i]);
                }
                list.add(_temp);
            }
        } finally {
            if (rs != null)
                rs.close();
            if (stmt != null)
                stmt.close();
            if (conn != null)
                conn.close();
        }
    }

}