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我已经尝试过 Janino，并且可以通过将 String 传递给 janino 编译器来执行动态类。

现在，我应该动态创建几个类，然后将它们导入另一个动态类。

一个例子：

  • 从 String 编译类 A
  • 从 String 编译类 B
  • 创建类 C，放入“import mypackage.A; import mypackage.B; etc...”
  • 编译类 C

我怎样才能达到这个结果？

我的第一个动态课程是：

package com.Flink.POJO;
public class RainPOJO {
    private String Altitude;
    private String City_name;
    private String Latitude;
    private String Longitude;
    private String Rainfall;
    private String Station_name;
    private String Time;

    public String getAltitude() {
        return Altitude;
    }

    public void setAltitude(String Altitude) {
        this.Altitude = Altitude;
    }
    public String getCity_name() {
        return City_name;
    }
    public void setCity_name(String City_name) {
        this.City_name = City_name;
    }
    public String getLatitude() {
        return Latitude;
    }
    public void setLatitude(String Latitude) {
        this.Latitude = Latitude;
    }
    public String getLongitude() {
        return Longitude;
    }
    public void setLongitude(String Longitude) {
        this.Longitude = Longitude;
    }
    public String getRainfall() {
        return Rainfall;
    }
    public void setRainfall(String Rainfall) {
        this.Rainfall = Rainfall;
    }
    public String getStation_name() {
        return Station_name;
    }
    public void setStation_name(String Station_name) {
        this.Station_name = Station_name;
    }
    public String getTime() {
        return Time;
    }
    public void setTime(String Time) {
        this.Time = Time;
    }
}

然后我必须从以下动态生成的类中调用该类：

import org.apache.flink.api.common.functions.MapFunction;
import java.util.ArrayList;
import com.google.gson.JsonObject;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.api.common.operators.base.JoinOperatorBase;
import com.Flink.POJO.RainPOJO;
public class FlinkExecutor {
    public FlinkExecutor() {}
    public static void main(String[] args) throws Exception {
        final ExecutionEnvironment env =  ExecutionEnvironment.getExecutionEnvironment();
        env.setDegreeOfParallelism(1);

        Source Rain = new Source("sensor", "rain");
        String path_Rain = Rain.getCSVPath();
        DataSet < RainPOJO > ds_s1 = env.readCsvFile("file://" + path_Rain)
        .ignoreFirstLine()
        .pojoType(RainPOJO.class, "table", "time", "longitude", "latitude", "average_rainfall", "maximum_rainfall");
        ds_s1.map(new MapRain(ds_s1.count()))
        .print();
    }
}

编译我使用的第一个类：

SimpleCompiler compiler = new SimpleCompiler();
compiler.cook(p_class);
ClassLoader classloader = compiler.getClassLoader();            
try {
    Class<?> cl = classloader.loadClass("com.Flink.POJO.RainPOJO");         
} catch (ClassNotFoundException e1) {
    e1.printStackTrace();
}

而对于第二个类，它包含主要方法：

    SimpleCompiler compiler = new SimpleCompiler(); 
    compiler.cook(this.allClass);
    try {
        Class<?> cl = compiler.getClassLoader().loadClass("FlinkExecutor");
         Method mainMeth = cl.getMethod("main", new Class[] { String[].class });
         String[] methArgs = new String[] { "" }; // one input
         mainMeth.invoke(null, new Object[] { methArgs });

    } catch (ClassNotFoundException | NoSuchMethodException | SecurityException | IllegalAccessException | IllegalArgumentException e) {
        e.printStackTrace();
    }

我得到的错误是：
org.codehaus.commons.compiler.CompileException: Line 8, Column 7: A class 'com.Flink.POJO.RainPOJO' could not be found

Janino 找不到类导入声明。

谢谢你，贾科莫

4

1 回答 1

0

从第一个编译器获取类加载器，将其设置为第二个编译器使用setParentClassLoader()

于 2019-09-19T11:30:15.833 回答