一、所需工具
1、phantomjs
官网下载http://phantomjs.org/download.html 国内镜像http://npm.taobao.org/dist/phantomjs/
2、EChartsConvert
https://gitee.com/saintlee/echartsconvert
二、Maven依赖
org.freemarker
freemarker
2.3.28
org.apache.httpcomponents
httpclient
4.5.7
com.alibaba
fastjson
1.2.56
三、运行EchartsConvert
1、安装phantomjs、EchartsConvert
解压 phantomjs-2.1.1-windows.zip 和 saintlee-echartsconvert-master.zip
2、命令行输入指令
命令行输入
笔者没有配置环境变量，完整输入为
C:\Users\Administrator\Desktop\phantomjs-2.1.1-windows\bin>phantomjs C:\Users\Administrator\Desktop\echartsconvert\echarts-convert.js -s -p 6666
显示echarts-convert server start success. [pid]=10364表明启动成功
四、java代码
1、结构
image.png
2、工具类
Http工具类
package com.mosband.genecharts.util;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
public class HttpUtil {
public static String post(String url, Map params, String charset)
throws ClientProtocolException, IOException {
String responseEntity = "";
// 创建CloseableHttpClient对象
CloseableHttpClient client = HttpClients.createDefault();
// 创建post方式请求对象
HttpPost httpPost = new HttpPost(url);
// 生成请求参数
List nameValuePairs = new ArrayList<>();
if (params != null) {
for (Entry entry : params.entrySet()) {
nameValuePairs.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
}
}
// 将参数添加到post请求中
httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs, charset));
// 发送请求，获取结果（同步阻塞）
CloseableHttpResponse response = client.execute(httpPost);
// 获取响应实体
HttpEntity entity = response.getEntity();
if (entity != null) {
// 按指定编码转换结果实体为String类型
responseEntity = EntityUtils.toString(entity, charset);
}
// 释放资源
EntityUtils.consume(entity);
response.close();
return responseEntity;
}
}
Freemarker工具类
package com.mosband.genecharts.util;
import java.io.File;
import java.io.IOException;
import java.io.StringWriter;
import java.util.Map;
import freemarker.template.Configuration;
import freemarker.template.Template;
import freemarker.template.TemplateException;
public class FreemarkerUtil {
private static final String path = FreemarkerUtil.class.getClassLoader().getResource("").getPath();
public static String generateString(String templateFileName, String templateDirectory, Map datas)
throws IOException, TemplateException {
Configuration configuration = new Configuration(Configuration.VERSION_2_3_0);
// 设置默认编码
configuration.setDefaultEncoding("UTF-8");
// 设置模板所在文件夹
configuration.setDirectoryForTemplateLoading(new File(path + templateDirectory));
// 生成模板对象
Template template = configuration.getTemplate(templateFileName);
// 将datas写入模板并返回
try (StringWriter stringWriter = new StringWriter()) {
template.process(datas, stringWriter);
stringWriter.flush();
return stringWriter.getBuffer().toString();
}
}
}
生成Echarts工具类
package com.mosband.genecharts.util;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import org.apache.http.client.ClientProtocolException;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
public class EchartsUtil {
private static String url = "http://localhost:6666";
private static final String SUCCESS_CODE = "1";
public static String generateEchartsBase64(String option) throws ClientProtocolException, IOException {
String base64 = "";
if (option == null) {
return base64;
}
option = option.replaceAll("\\s+", "").replaceAll("\"", "'");
// 将option字符串作为参数发送给echartsConvert服务器
Map params = new HashMap<>();
params.put("opt", option);
String response = HttpUtil.post(url, params, "utf-8");
// 解析echartsConvert响应
JSONObject responseJson = JSON.parseObject(response);
String code = responseJson.getString("code");
// 如果echartsConvert正常返回
if (SUCCESS_CODE.equals(code)) {
base64 = responseJson.getString("data");
}
// 未正常返回
else {
String string = responseJson.getString("msg");
throw new RuntimeException(string);
}
return base64;
}
}
option.ftl
{
title: {
text:'${title}',
x:'middle',
textAlign:'center'
},
xAxis: {
type: 'category',
data: ${categories}
},
yAxis: {
type: 'value'
},
series: [{
data: ${values},
type: 'bar'
}]
}
测试类
package com.mosband.genecharts;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.HashMap;
import org.apache.http.client.ClientProtocolException;
import com.alibaba.fastjson.JSON;
import com.mosband.genecharts.util.EchartsUtil;
import com.mosband.genecharts.util.FreemarkerUtil;
import freemarker.template.TemplateException;
import sun.misc.BASE64Decoder;
public class App {
public static void main(String[] args) throws ClientProtocolException, IOException, TemplateException {
// 变量
String title = "水果";
String[] categories = new String[] { "苹果", "香蕉", "西瓜" };
int[] values = new int[] { 3, 2, 1 };
// 模板参数
HashMap datas = new HashMap<>();
datas.put("categories", JSON.toJSONString(categories));
datas.put("values", JSON.toJSONString(values));
datas.put("title", title);
// 生成option字符串
String option = FreemarkerUtil.generateString("option.ftl", "/com/mosband/genecharts/template", datas);
// 根据option参数
String base64 = EchartsUtil.generateEchartsBase64(option);
System.out.println("BASE64:" + base64);
generateImage(base64, "C:/Users/Administrator/Desktop/test.png");
}
public static void generateImage(String base64, String path) throws IOException {
BASE64Decoder decoder = new BASE64Decoder();
try (OutputStream out = new FileOutputStream(path)){
// 解密
byte[] b = decoder.decodeBuffer(base64);
for (int i = 0; i < b.length; ++i) {
if (b[i] < 0) {
b[i] += 256;
}
}
out.write(b);
out.flush();
}
}
}
五、效果
控制台打印结果
BASE64:iVBORw0KGgoAAAANSUhEUgAAA...
test.png
image.png