database.java

JSP华源网校+西部软件JSP版

package org.jetic.web;

import java.sql.ResultSet;
import java.sql.Statement;
import java.util.Vector;
import javax.servlet.http.HttpServletRequest;
import org.jetic.util.Format;

/**
 * Title:        经天科技
 * Description:
 * Copyright:    Copyright (c) 2001
 * Company:      www.jetic.org 经天
 * @author hover
 * @version 1.0
 */

public class DataBase {
    private java.sql.Statement stmt;
    private javax.servlet.http.HttpServletRequest request;
    private String table;
    private int ID = 0;
    private Vector fields;

    public DataBase() {
        fields = new Vector(20);
    }

    public boolean addField(DataField field) {
        if (indexOfField(field) > -1)    return false;
        fields.addElement(field);
        return true;
    }

    public boolean set(String property, String value) {
        int index = indexOfField(property);

        // 找不到属性
        if (index < 0) return false;

        DataField field = (DataField)(fields.elementAt(index));
        field.setValue(value);

        return true;
    }

    public boolean set(String property) {
        String value = request.getParameter(property);

        // 参数为空值
        if (value == null)  return false;

        return set(property, value);
    }

    public String getPlain(String property) {
        int index = indexOfField(property);
        if (index < 0)  return null;
        DataField field = (DataField)(fields.elementAt(index));
        return new String(field.getValue());
    }

    public String getInput(String property) {
        return Format.toHtmlInput(getPlain(property));
    }

    public String get(String property) {
        return Format.toHtml(getPlain(property));
    }

    public boolean isSavable() {
        Vector validFields = new Vector(20);
        DataField field;
        int index;

        // 取出有效字段
        for (index = 0; index < fields.size(); index++) {
            field = (DataField)(fields.elementAt(index));
            if (field.saveRequired)  validFields.addElement(field);
        }

        for (index = 0; index < validFields.size(); index++) {
            field = (DataField)(validFields.elementAt(index));
            // TODO
            System.out.println("正在检查字段：" + field.name + "，值：" + field.getValue());
            if (field.getValue() == null || field.getValue().length() < 1)
                return false;
        }

        return true;
    }

    public boolean isUpdatable() {
        Vector validFields = new Vector(20);
        DataField field;
        int index;

        if (ID < 1) return false;

        // 取出有效字段
        for (index = 0; index < fields.size(); index++) {
            field = (DataField)(fields.elementAt(index));
            if (field.updateRequired)  validFields.addElement(field);
        }

        for (index = 0; index < validFields.size(); index++) {
            field = (DataField)(validFields.elementAt(index));
            if (field.getValue() == null || field.getValue().length() < 1)
                return false;
        }

        return true;
    }

    public boolean isDeletable() {
        return (ID > 0);
    }

    public boolean save() {
        Vector validFields = new Vector(20);
        DataField field;
        int index;
        String sql;

        sql = "INSERT INTO " + table + " (";

        // 取出有效字段
        for (index = 0; index < fields.size(); index++) {
            field = (DataField)(fields.elementAt(index));
            if (field.savable)  validFields.addElement(field);
        }

        for (index = 0; index < validFields.size(); index++) {
            field = (DataField)(validFields.elementAt(index));
            sql += field.fieldName;
            if (index < validFields.size() - 1) sql += ",";
        }

        sql += ") VALUES (";

        for (index = 0; index < validFields.size(); index++) {
            field = (DataField)(validFields.elementAt(index));
            if (field.type == DataField.TYPE_INT)
                sql += field.getValue();
            else
                sql += "'" + Format.toSql(field.getValue()) + "'";
            if (index < validFields.size() - 1) sql += ",";
        }

        sql += ")";

        try {
            stmt.executeUpdate(sql);
            return true;
        }
        catch (Exception ex) {
            ex.printStackTrace(System.err);
            return false;
        }
    }

    public boolean update() {
        Vector validFields = new Vector(20);
        DataField field;
        int index;
        String sql;

        sql = "UPDATE " + table + " SET ";

        // 取出有效字段
        for (index = 0; index < fields.size(); index++) {
            field = (DataField)(fields.elementAt(index));
            if (field.updatable)  validFields.addElement(field);
        }

        for (index = 0; index < validFields.size(); index++) {
            field = (DataField)(validFields.elementAt(index));
            sql += field.fieldName + "=";
            if (field.type == DataField.TYPE_INT)
                sql += field.getValue();
            else
                sql += "'" + Format.toSql(field.getValue()) + "'";
            if (index < validFields.size() - 1) sql += ",";
        }

        sql += " WHERE [ID] = " + ID;

        try {
            stmt.executeUpdate(sql);
            return true;
        }
        catch (Exception ex) {
            ex.printStackTrace(System.err);
            return false;
        }
    }

    public boolean delete() {
        String sql = "DELETE FROM " + table + " WHERE [ID] =" + ID;
        try {
            stmt.executeUpdate(sql);
            return true;
        }
        catch (Exception ex) {
            ex.printStackTrace(System.err);
            return false;
        }
    }

    public String[] getDataFields() {
        String[] f = new String[fields.size() - 1];
        DataField field;
        int index;

        for (index = 1; index < fields.size(); index++) {
            field = (DataField)(fields.elementAt(index));
            f[index - 1] = field.fieldName;
        }

        return f;
    }

    // 内部私有方法
    private int indexOfField(String property) {
        DataField field;
        int index;

        for (index = 0; index < fields.size(); index++) {
            field = (DataField)(fields.elementAt(index));
            if (field.name.equals(property))    return index;
        }

        return -1;
    }
    private int indexOfField(DataField field) {
        return fields.indexOf(field);
    }
    private String valueOfField(int index) {
        DataField field = (DataField)(fields.elementAt(index));
        return field.getValue();
    }
    private String valueOfField(String property) {
        return valueOfField(indexOfField(property));
    }
    private DataField getField(int index) {
        return (DataField)(fields.elementAt(index));
    }
    private DataField getField(String property) {
        return getField(indexOfField(property));
    }

    // 属性
    public Vector getFields() {
        return fields;
    }
    public java.sql.Statement getStmt() {
        return stmt;
    }
    public void setStmt(java.sql.Statement newStmt) {
        stmt = newStmt;
    }
    public void setTable(String newTable) {
        table = newTable;
    }
    public String getTable() {
        return table;
    }
    public void setRequest(javax.servlet.http.HttpServletRequest newRequest) {
        request = newRequest;
    }
    public javax.servlet.http.HttpServletRequest getRequest() {
        return request;
    }
    public void setID(int newID) {
        ID = newID;

        DataField field;
        int index;
        String sql;

        sql = "SELECT ";

        for (index = 0; index < fields.size(); index++) {
            field = (DataField)(fields.elementAt(index));
            sql += field.fieldName;
            if (index < fields.size() - 1)  sql += ",";
        }

        sql += " FROM " + table + " WHERE [ID] = " + ID;

        try {
            ResultSet rs = stmt.executeQuery(sql);
            if (rs.next()) {
                for (index = 0; index < fields.size(); index++) {
                    field = (DataField)(fields.elementAt(index));
                    field.setValue(rs.getString(index + 1));
                }
            }
            rs.close();
        }
        catch (Exception ex) {
            ex.printStackTrace(System.err);
        }
    }
    public int getID() {
        return ID;
    }
}