toolkit.java

以前做的一个j2ee的项目

package gov.gdlt.ssgly.taxcore.comm.util;

import javax.faces.context.FacesContext;
import java.util.Map;
import javax.faces.context.ExternalContext;
import javax.faces.el.ValueBinding;
import javax.faces.el.MethodBinding;
import javax.servlet.http.HttpServletRequest;
import javax.faces.application.FacesMessage;
import gov.gdlt.ssgly.taxcore.comm.config.ApplicationContext;
import java.io.OutputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.FileInputStream;
import java.io.UnsupportedEncodingException;

/**
 * 在此提供公共的常用静态方法实现．
 *
 * <p>Title: ISsglyService</p>
 * <p>Description: 税收管理员系统</p>
 * <p>Copyright: Copyright (c) 2005 广州市地方税务局</p>
 * <p>Company: 信息中心</p>
 * @author Lemon
 * @version 1.0
 * @since 2005.8.8.
 * @author 郑毅晖
 * @version 1.1
 * @since 2005.8.23
 * 加入了toFile,fromFile,toStringBuffer等函数
 */

public class Toolkit {
    public static void putGlobalMsg(String msg) {
        FacesContext context = FacesContext.getCurrentInstance();
        context.addMessage(null, new FacesMessage(msg));
    }

    public static void setExprValue(String expr, String value) {
        FacesContext context = FacesContext.getCurrentInstance();
        ValueBinding binding = context.getApplication().createValueBinding(expr);

        binding.setValue(context, value);
    }

    public static String getParameterFromContextMap(String paramName) {
        FacesContext context = FacesContext.getCurrentInstance();
        ExternalContext ec = context.getExternalContext();
        Map parameterMap = ec.getRequestParameterMap();

        return (String) parameterMap.get(paramName);
    }

    public static Object eval(String expr) {
        FacesContext context = FacesContext.getCurrentInstance();
        ValueBinding binding = context.getApplication().createValueBinding(expr);

        return binding.getValue(context);
    }

    public static Object evalMethod(String expr,
                                    java.lang.Class[] typeParams,
                                    java.lang.Object[] params) {
        FacesContext context = FacesContext.getCurrentInstance();
        MethodBinding binding = context.getApplication().createMethodBinding(
                expr, typeParams);

        return binding.invoke(context, params);
    }

    public static String getRemoteAddr() {
        FacesContext context = FacesContext.getCurrentInstance();
        ExternalContext ec = context.getExternalContext();
        HttpServletRequest request = (HttpServletRequest) ec.getRequest();

        return request.getRemoteAddr();
    }

    /**
     * 把字节数组输出到文件中
     * @param byteArray：byte[] 要被输出的字节数组
     * @param filename：String 输出文件名
     * @return int<br>
     *    RET_SUCCESS 执行成功<br>
     *    RET_FAIL 执行失败
     */
    public static int toFile(byte[] byteArray, String filename) {
        OutputStream out = null;

        try {
            out = new FileOutputStream(filename);
            out.write(byteArray);
            out.close();
        } catch (Exception ex) {
            ex.printStackTrace();
            return ApplicationContext.RET_FAIL;
        }
        return ApplicationContext.RET_SUCCESS;
    }

    /**
     * 从文件中读入并存放到字节数组中
     * @param filename：String 文件名
     * @return byte[]<br>
     *    非空：成功
     *    NULL：失败
     */
    public static byte[] fromFile(String filename) {
        InputStream in = null;
        byte[] result = null;

        try {
            in = new FileInputStream(filename);
            result = new byte[in.available()];
            in.read(result);
            in.close();
        } catch (Exception ex) {
            ex.printStackTrace();
            return null;
        }
        return result;
    }

    /**
     * 把字节数组转换成字符串缓冲
     * @param byteArray：byte[] 字节数组
     * @return StringBuffer<br>
     *    非空：成功
     *    NULL：失败
     */
    public static StringBuffer toStringBuffer(byte[] byteArray) {
        return new StringBuffer(new String(byteArray));
    }

    /**
     * 把字节数组转换成字符串缓冲（可指定使用的字符集）
     * @param byteArray：byte[] 字节数组
     * @param charset：String 字符集
     * @return StringBuffer<br>
     *    非空：成功
     *    NULL：失败
     */
    public static StringBuffer toStringBuffer(byte[] byteArray, String charset) {
        try {
            return new StringBuffer(new String(byteArray, charset));
        } catch (UnsupportedEncodingException ex) {
            ex.printStackTrace();
            return null;
        }
    }

}