使用技術(shù)
itext.jar : 將byte文件輸入流轉(zhuǎn)換為圖片，pdf等
html2canvas.js ：將html頁(yè)面區(qū)域截圖為base64編碼的圖片資源
java+js
1. 準(zhǔn)備資源
itext.jar
www.baidu.com
html2canvas.js
www.baidu.com
2.前端代碼：
//進(jìn)行截圖操作，document.querySelector("body") 為要截圖的區(qū)域
function test() {
html2canvas(document.querySelector("body"), {
onrendered: function (canvas) {
var dataUrl = canvas.toDataURL('image/png');
var formData = new FormData(); //模擬表單對(duì)象
formData.append("imgData", convertBase64UrlToBlob(dataUrl)); //寫(xiě)入數(shù)據(jù)
var xhr = new XMLHttpRequest(); //數(shù)據(jù)傳輸方法
xhr.open("POST", "http://localhost:8080/pdf"); //配置傳輸方式及地址
xhr.send(formData);
xhr.onreadystatechange = function () { //回調(diào)函數(shù)
};
}
});
}
//格式化圖片base64編碼轉(zhuǎn)換為byte文件流
function convertBase64UrlToBlob(urlData){
//去掉url的頭，并轉(zhuǎn)換為byte
var bytes=window.atob(urlData.split(',')[1]);
//處理異常,將ascii碼小于0的轉(zhuǎn)換為大于0
var ab = new ArrayBuffer(bytes.length);
var ia = new Uint8Array(ab);
for (var s = 0;s<bytes.length;s++){
ia[s] = bytes.charCodeAt(s);
}
return new Blob( [ab] , {type : 'image/png'});
}
<body onclick="test()">//調(diào)用截圖方法即可
3.后端代碼：
@RequestMapping(value = "/pdf",method = RequestMethod.POST)
public void test(MultipartHttpServletRequest request, HttpServletResponse response) throws IOException {
String filePath = "D:\\blog\\exportPdf2.pdf";
String imagePath = "D:\\blog\\exportImg2.png";
Document document = new Document();
try{
Map getMap = request.getFileMap();
MultipartFile mfile = (MultipartFile) getMap.get("imgData"); //獲取數(shù)據(jù)
InputStream file = mfile.getInputStream();
byte[] fileByte = FileCopyUtils.copyToByteArray(file);
FileImageOutputStream imageOutput = new FileImageOutputStream(new File(imagePath));//打開(kāi)輸入流
imageOutput.write(fileByte, 0, fileByte.length);//生成本地圖片文件
imageOutput.close();
PdfWriter.getInstance(document, new FileOutputStream(filePath)); //itextpdf文件
document.open();
document.add(new Paragraph("JUST TEST ..."));
Image image = Image.getInstance(imagePath); //itext-pdf-image
float heigth = image.getHeight();
float width = image.getWidth();
int percent = getPercent2(heigth, width); //按比例縮小圖片
image.setAlignment(Image.MIDDLE);
image.scalePercent(percent+3);
document.add(image);
document.close();
}catch (DocumentException de) {
System.err.println(de.getMessage());
}
catch (Exception e) {
e.printStackTrace();
}
}
private static int getPercent2(float h, float w) {
int p = 0;
float p2 = 0.0f;
p2 = 530 / w * 100;
p = Math.round(p2);
return p;
}
4 包名
import com.itextpdf.text.Document;
import com.itextpdf.text.DocumentException;
import com.itextpdf.text.Image;
import com.itextpdf.text.Paragraph;
import com.itextpdf.text.pdf.PdfWriter;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.stereotype.Controller;
import org.springframework.util.FileCopyUtils;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import javax.imageio.stream.FileImageOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Map;
4 前端截圖，訪問(wèn)后端接口，保存截圖文件到本地為pdf或者其他格式的文件。
有興趣的同學(xué)可以把后端改為下載文件到本地
5 項(xiàng)目源碼地址
https://github.com/zhangjy520/learn_java/tree/master/boot
到此這篇關(guān)于html轉(zhuǎn)pdf截圖保存功能的實(shí)現(xiàn)的文章就介紹到這了,更多相關(guān)html轉(zhuǎn)pdf截圖保存內(nèi)容請(qǐng)搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持腳本之家！
