需求背景
需要将端上传过来的svg文件解析为字符串，然后再生成jpeg格式图片，再将图片转成Base64格式进行使用
实现代码
首先引入如下以来。版本一定按照这个来，高版本会出现各种类丢失的问题。
<dependency>
<groupId>batik</groupId>
<artifactId>batik-svggen</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-awt-util</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-bridge</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-css</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-dom</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-gvt</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-parser</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-script</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-svg-dom</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-transcoder</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-util</artifactId>
<version>1.6</version>
</dependency>
<dependency>
<groupId>batik</groupId>
<artifactId>batik-xml</artifactId>
<version>1.6</version>
</dependency>
<!-- 此处不能使用2.9.1版本，使用2.9.1生成png会失败 -->
<dependency>
<groupId>xerces</groupId>
<artifactId>xercesImpl</artifactId>
<version>2.9.0</version>
</dependency>
<dependency>
<groupId>org.axsl.org.w3c.dom.svg</groupId>
<artifactId>svg-dom-java</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>org.w3c.css</groupId>
<artifactId>sac</artifactId>
<version>1.3</version>
</dependency>
再就是工具类代码
package com.netease.music.sociallive.game.common.utils;
import com.netease.music.sociallive.game.common.constant.StreamConst;
import lombok.extern.slf4j.Slf4j;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.JPEGTranscoder;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Base64;
@Slf4j
public class SvgImageUtil {
private final static int BUF_SIZE = 1024;
private final static String PREFIX = "data:image/jpeg;base64,";
/**
* 将svg字符串转为base64
*
* @param svgCode svg字符串
* @param filePath 临时存储文件的地址
* @return base64格式表示的jpeg文件
*/
public static String convertSvgToBase64(String svgCode, String filePath) {
String base64Code = "";
File file = new File(filePath);
FileOutputStream outputStream = null;
try {
file.createNewFile();
outputStream = new FileOutputStream(file);
byte[] bytes = svgCode.getBytes(StandardCharsets.UTF_8);
JPEGTranscoder t = new JPEGTranscoder();
//压缩图片质量
t.addTranscodingHint(JPEGTranscoder.KEY_QUALITY, 0.50f);
TranscoderInput input = new TranscoderInput(new ByteArrayInputStream(bytes));
TranscoderOutput output = new TranscoderOutput(outputStream);
t.transcode(input, output);
//将svg转为jpeg文件暂存在本地磁盘
outputStream.flush();
//本地jpeg文件读取后转化为base64格式
base64Code = Base64.getEncoder().encodeToString(toByteArray(filePath));
//删除本地暂存的文件
File f = new File(filePath);
if (f.isFile() && f.exists()) {
f.delete();
}
} catch (Exception e) {
log.error("@@图片处理@@ svg转化为base64失败", e);
} finally {
if (outputStream != null) {
try {
outputStream.close();
} catch (Exception e) {
log.error("@@图片处理@@ 关闭io流失败", e);
}
}
}
return PREFIX + base64Code;
}
/**
* 将本地文件读取到字节数组中
*
* @param filePath 文件地址
* @return res
*/
private static byte[] toByteArray(String filePath) {
File f = new File(filePath);
if (!f.exists()) {
log.error("@图片处理@@ 未找到本地图片");
return new byte[0];
}
ByteArrayOutputStream bos = new ByteArrayOutputStream((int) f.length());
BufferedInputStream in = null;
try {
in = new BufferedInputStream(new FileInputStream(f));
byte[] buffer = new byte[BUF_SIZE];
int len = StreamConst.NOTHING;
while (-1 != (len = in.read(buffer, StreamConst.NOTHING, BUF_SIZE))) {
bos.write(buffer, 0, len);
}
} catch (Exception e) {
log.error("@图片处理@@ svg转化为base64失败", e);
} finally {
try {
if (in != null) {
in.close();
}
bos.close();
} catch (IOException e) {
log.error("@@图片处理@@ 关闭io流失败", e);
}
}
return bos.toByteArray();
}
}
功能测试
public static void main(String[] args) {
try {
String svgCode = "<svg height=\"210\" width=\"500\">\n" +
" <polygon points=\"220,10 250,190 160,210\"\n" +
" style=\"fill:lime;stroke:purple;stroke-width:1\"/>\n" +
"</svg>";
System.out.println(convertSvgToBase64(svgCode, "/Users/fps/Desktop/" + Math.random() * 10 + ".jpeg"));
} catch (Exception e) {
log.error("e", e);
}
}
可以看到生成了base64字符串
进行转化后能够复原出图片
