org.smart4j.framework.util.WebUtil Maven / Gradle / Ivy
package org.smart4j.framework.util;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.FilenameUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.smart4j.framework.FrameworkConstant;
/**
* Web 操作工具类
*
* @author huangyong
* @since 1.0
*/
public class WebUtil {
private static final Logger logger = LoggerFactory.getLogger(WebUtil.class);
/**
* 将数据以 JSON 格式写入响应中
*/
public static void writeJSON(HttpServletResponse response, Object data) {
try {
// 设置响应头
response.setContentType("application/json"); // 指定内容类型为 JSON 格式
response.setCharacterEncoding(FrameworkConstant.UTF_8); // 防止中文乱码
// 向响应中写入数据
PrintWriter writer = response.getWriter();
writer.write(JsonUtil.toJSON(data)); // 转为 JSON 字符串
writer.flush();
writer.close();
} catch (Exception e) {
logger.error("在响应中写数据出错！", e);
throw new RuntimeException(e);
}
}
/**
* 将数据以 HTML 格式写入响应中（在 JS 中获取的是 JSON 字符串，而不是 JSON 对象）
*/
public static void writeHTML(HttpServletResponse response, Object data) {
try {
// 设置响应头
response.setContentType("text/html"); // 指定内容类型为 HTML 格式
response.setCharacterEncoding(FrameworkConstant.UTF_8); // 防止中文乱码
// 向响应中写入数据
PrintWriter writer = response.getWriter();
writer.write(JsonUtil.toJSON(data)); // 转为 JSON 字符串
writer.flush();
writer.close();
} catch (Exception e) {
logger.error("在响应中写数据出错！", e);
throw new RuntimeException(e);
}
}
/**
* 从请求中获取所有参数（当参数名重复时，用后者覆盖前者）
*/
public static Map getRequestParamMap(HttpServletRequest request) {
Map paramMap = new LinkedHashMap();
try {
String method = request.getMethod();
if (method.equalsIgnoreCase("put") || method.equalsIgnoreCase("delete")) {
String queryString = CodecUtil.decodeURL(StreamUtil.getString(request.getInputStream()));
if (StringUtil.isNotEmpty(queryString)) {
String[] qsArray = StringUtil.splitString(queryString, "&");
if (ArrayUtil.isNotEmpty(qsArray)) {
for (String qs : qsArray) {
String[] array = StringUtil.splitString(qs, "=");
if (ArrayUtil.isNotEmpty(array) && array.length == 2) {
String paramName = array[0];
String paramValue = array[1];
if (checkParamName(paramName)) {
paramMap.put(paramName, paramValue);
}
}
}
}
}
} else {
Enumeration paramNames = request.getParameterNames();
while (paramNames.hasMoreElements()) {
String paramName = paramNames.nextElement();
if (checkParamName(paramName)) {
String[] paramValues = request.getParameterValues(paramName);
if (ArrayUtil.isNotEmpty(paramValues)) {
if (paramValues.length == 1) {
paramMap.put(paramName, paramValues[0]);
} else {
StringBuilder paramValue = new StringBuilder("");
for (int i = 0; i < paramValues.length; i++) {
paramValue.append(paramValues[i]);
if (i != paramValues.length - 1) {
paramValue.append(StringUtil.SEPARATOR);
}
}
paramMap.put(paramName, paramValue.toString());
}
}
}
}
}
} catch (Exception e) {
logger.error("获取请求参数出错！", e);
throw new RuntimeException(e);
}
return paramMap;
}
private static boolean checkParamName(String paramName) {
return !paramName.equals("_"); // 忽略 jQuery 缓存参数
}
/**
* 转发请求
*/
public static void forwardRequest(String path, HttpServletRequest request, HttpServletResponse response) {
try {
request.getRequestDispatcher(path).forward(request, response);
} catch (Exception e) {
logger.error("转发请求出错！", e);
throw new RuntimeException(e);
}
}
/**
* 重定向请求
*/
public static void redirectRequest(String path, HttpServletRequest request, HttpServletResponse response) {
try {
response.sendRedirect(request.getContextPath() + path);
} catch (Exception e) {
logger.error("重定向请求出错！", e);
throw new RuntimeException(e);
}
}
/**
* 发送错误代码
*/
public static void sendError(int code, String message, HttpServletResponse response) {
try {
response.sendError(code, message);
} catch (Exception e) {
logger.error("发送错误代码出错！", e);
throw new RuntimeException(e);
}
}
/**
* 判断是否为 AJAX 请求
*/
public static boolean isAJAX(HttpServletRequest request) {
return request.getHeader("X-Requested-With") != null;
}
/**
* 获取请求路径
*/
public static String getRequestPath(HttpServletRequest request) {
String servletPath = request.getServletPath();
String pathInfo = StringUtil.defaultIfEmpty(request.getPathInfo(), "");
return servletPath + pathInfo;
}
/**
* 从 Cookie 中获取数据
*/
public static String getCookie(HttpServletRequest request, String name) {
String value = "";
try {
Cookie[] cookieArray = request.getCookies();
if (cookieArray != null) {
for (Cookie cookie : cookieArray) {
if (StringUtil.isNotEmpty(name) && name.equals(cookie.getName())) {
value = CodecUtil.decodeURL(cookie.getValue());
break;
}
}
}
} catch (Exception e) {
logger.error("获取 Cookie 出错！", e);
throw new RuntimeException(e);
}
return value;
}
/**
* 下载文件
*/
public static void downloadFile(HttpServletResponse response, String filePath) {
try {
String originalFileName = FilenameUtils.getName(filePath);
String downloadedFileName = new String(originalFileName.getBytes("GBK"), "ISO8859_1"); // 防止中文乱码
response.setContentType("application/octet-stream");
response.addHeader("Content-Disposition", "attachment;filename=\"" + downloadedFileName + "\"");
InputStream inputStream = new BufferedInputStream(new FileInputStream(filePath));
OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
StreamUtil.copyStream(inputStream, outputStream);
} catch (Exception e) {
logger.error("下载文件出错！", e);
throw new RuntimeException(e);
}
}
/**
* 设置 Redirect URL 到 Session 中
*/
public static void setRedirectUrl(HttpServletRequest request, String sessionKey) {
if (!isAJAX(request)) {
String requestPath = getRequestPath(request);
request.getSession().setAttribute(sessionKey, requestPath);
}
}
/**
* 创建验证码
*/
public static String createCaptcha(HttpServletResponse response) {
StringBuilder captcha = new StringBuilder();
try {
// 参数初始化
int width = 60; // 验证码图片的宽度
int height = 25; // 验证码图片的高度
int codeCount = 4; // 验证码字符个数
int codeX = width / (codeCount + 1); // 字符横向间距
int codeY = height - 4; // 字符纵向间距
int fontHeight = height - 2; // 字体高度
int randomSeed = 10; // 随机数种子
char[] codeSequence = { // 验证码中可出现的字符
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'
};
// 创建图像
BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics2D g = bi.createGraphics();
// 将图像填充为白色
g.setColor(Color.WHITE);
g.fillRect(0, 0, width, height);
// 设置字体
g.setFont(new Font("Courier New", Font.BOLD, fontHeight));
// 绘制边框
g.setColor(Color.BLACK);
g.drawRect(0, 0, width - 1, height - 1);
// 产生随机干扰线（160条）
g.setColor(Color.WHITE);
// 创建随机数生成器
Random random = new Random();
for (int i = 0; i < 160; i++) {
int x = random.nextInt(width);
int y = random.nextInt(height);
int xl = random.nextInt(12);
int yl = random.nextInt(12);
g.drawLine(x, y, x + xl, y + yl);
}
// 生成随机验证码
int red, green, blue;
for (int i = 0; i < codeCount; i++) {
// 获取随机验证码
String validateCode = String.valueOf(codeSequence[random.nextInt(randomSeed)]);
// 随机构造颜色值
red = random.nextInt(255);
green = random.nextInt(255);
blue = random.nextInt(255);
// 将带有颜色的验证码绘制到图像中
g.setColor(new Color(red, green, blue));
g.drawString(validateCode, (i + 1) * codeX - 6, codeY);
// 将产生的随机数拼接起来
captcha.append(validateCode);
}
// 禁止图像缓存
response.setHeader("Cache-Control", "no-store");
response.setHeader("Pragma", "no-cache");
response.setDateHeader("Expires", 0);
// 设置响应类型为 JPEG 图片
response.setContentType("image/jpeg");
// 将缓冲图像写到 Servlet 输出流中
ServletOutputStream sos = response.getOutputStream();
ImageIO.write(bi, "jpeg", sos);
sos.close();
} catch (Exception e) {
logger.error("创建验证码出错！", e);
throw new RuntimeException(e);
}
return captcha.toString();
}
/**
* 是否为 IE 浏览器
*/
public boolean isIE(HttpServletRequest request) {
String agent = request.getHeader("User-Agent");
return agent != null && agent.contains("MSIE");
}
}
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