Java利用Phantomjs实现生成图片的方法

"use strict";
var page = require('webpage').create(),
  system = require('system'),
  address, output, size;

if (system.args.length < 3 || system.args.length > 5) {
  console.log('Usage: rasterize.js URL filename [paperwidth*paperheight|paperformat] [zoom]');
  console.log(' paper (pdf output) examples: "5in*7.5in", "10cm*20cm", "A4", "Letter"');
  console.log(' image (png/jpg output) examples: "1920px" entire page, window width 1920px');
  console.log('                  "800px*600px" window, clipped to 800x600');
  phantom.exit(1);
} else {
  address = system.args[1];
  output = system.args[2];
  page.viewportSize = { width: 800, height: 200 };
  if (system.args.length > 3 && system.args[2].substr(-4) === ".pdf") {
    size = system.args[3].split('*');
    page.paperSize = size.length === 2 &#63; { width: size[0], height: size[1], margin: '0px' }
                      : { format: system.args[3], orientation: 'portrait', margin: '1cm' };
  } else if (system.args.length > 3 && system.args[3].substr(-2) === "px") {
    size = system.args[3].split('*');
    if (size.length === 2) {
      var pageWidth = parseInt(size[0].substr(0,size[0].indexOf("px")), 10);
      var pageHeight = parseInt(size[1].substr(0,size[1].indexOf("px")), 10);
      page.viewportSize = { width: pageWidth, height: pageHeight };
      page.clipRect = { top: 0, left: 0, width: pageWidth, height: pageHeight };
    } else {
      var pageWidth = parseInt(system.args[3].substr(0,system.args[3].indexOf("px")), 10);
      var pageHeight = parseInt(pageWidth * 3/4, 10); // it's as good an assumption as any
      page.viewportSize = { width: pageWidth, height: pageHeight };
    }
  }
  if (system.args.length > 4) {
    page.zoomFactor = system.args[4];
  }
  page.open(address, function (status) {
    if (status !== 'success') {
      console.log('Unable to load the address!');
      phantom.exit(1);
    } else {
      window.setTimeout(function () {
        page.render(output);
        phantom.exit();
      }, 200);
    }
  });
}

package test;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.FileUtils;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * 网页转图片处理类，使用外部CMD
 *
 * @author lekkoli
 */
@Slf4j
public class PhantomTools {

  /**
   * 可执行文件phantomjs.exe路径
   */
  private final String phantomjsPath;
  /**
   * 快照图生成JS路径
   */
  private final String rasterizePath;
  /**
   * 临时图片前缀
   */
  private static final String FILE_PREFIX = "TIG-AE-";
  /**
   * 临时图片后缀
   */
  private static final String FILE_SUFFIX = ".jpg";

  /**
   * 构造参数
   * 获取phantomjs路径
   */
  public PhantomTools() {
    String bootPath = new File(this.getClass().getResource("/").getPath()).getPath();
    phantomjsPath = String.join(File.separator, bootPath, "phantomjs-2.1.1-windows", "bin", "phantomjs");
    rasterizePath = String.join(File.separator, bootPath, "phantomjs-2.1.1-windows", "examples", "rasterize.js");
  }

  /**
   * url 中需要转义的字符
   * 1. + URL 中+号表示空格 %2B
   * 2. 空格 URL中的空格可以用+号或者编码 %20
   * 3. / 分隔目录和子目录 %2F
   * 4. ? 分隔实际的 URL 和参数 %3F
   * 5. % 指定特殊字符 %25
   * 6. # 表示书签 %23
   * 7. & URL 中指定的参数间的分隔符 %26
   * 8. = URL 中指定参数的值 %3D
   *
   * @param url 需要转义的URL
   * @return 转义后的URL
   */
  public String parseUrl(String url) {
    String parsedUrl = StringUtils.replace(url, "&", "%26");
    log.info("[解析后的URL：{}]", parsedUrl);
    return parsedUrl;
  }

  /**
   * 根据URL生成指定fileName的字节数组
   *
   * @param url 请求URL
   * @return 图片字节数组
   */
  public byte[] create(String url) {
    return create(url, null);
  }

  /**
   * 根据URL生成指定fileName的字节数组
   *
   * @param url 请求URL
   * @param size 指定图片尺寸，例如：1000px*800px
   * @return 图片字节数组
   */
  public byte[] create(String url, String size) {
    // 服务器文件存放地址
    String filePath = FileUtils.getTempDirectoryPath() + FILE_PREFIX + UUID.randomUUID().toString() + FILE_SUFFIX;
    try {
      // 执行快照命令
      String command = String.join(StringUtils.SPACE, phantomjsPath, rasterizePath, url, filePath, size);
      log.info("[执行命令：{}]", command);
      // 执行命令操作
      Process process = Runtime.getRuntime().exec(command);
      // 一直挂起，直到子进程执行结束，返回值0表示正常退出
      if (process.waitFor() != 0) {
        log.error("[执行本地Command命令失败] [Command：{}]", command);
        return new byte[0];
      }
      // 判断生成的图片是否存在
      File file = FileUtils.getFile(filePath);
      if (!file.exists()) {
        log.error("[本地文件\"{}\"不存在]", file.getName());
        return new byte[0];
      }
      // 将快照图片生成字节数组
      byte[] bytes = IOUtils.toByteArray(new FileInputStream(file));
      log.info("[图片生成结束] [图片大小：{}KB]", bytes.length / 1024);
      return bytes;
    } catch (IOException | InterruptedException e) {
      log.error("[图片生成失败]", e);
    } finally {
      FileUtils.deleteQuietly(FileUtils.getFile(filePath));
    }
    return new byte[0];
  }
}

public Process exec(String[] cmdarray, String[] envp, File dir)
  throws IOException {
  return new ProcessBuilder(cmdarray)
    .environment(envp)
    .directory(dir)
    .start();
}

public static void main(String[] arg) throws IOException {
  String url = "https://www.cnblogs.com/ason-wxs/";
  PhantomTools phantomTools = new PhantomTools();
  String parsedUrl = phantomTools.parseUrl(url);
  byte[] byteImg = phantomTools.create(parsedUrl);
  File descFile = new File(FileUtils.getTempDirectoryPath() + "test.png");
  FileUtils.touch(descFile);
  FileUtils.writeByteArrayToFile(descFile, byteImg);
}