Java 在当前线程、初始化中未找到OpenGL上下文

我遇到了OpenGL涉及的一些问题。我得到一个java.lang.RuntimeException：在当前线程中找不到OpenGL上下文。错误下面我将发布我的堆栈打印输出和代码。帮助我学习OpenGL

java.lang.RuntimeException: No OpenGL context found in the current thread.
    at org.lwjgl.opengl.GLContext.getCapabilities(GLContext.java:124)
    at org.lwjgl.opengl.ARBShaderObjects.glDeleteObjectARB(ARBShaderObjects.java:63)
    at mygame.Box.createShader(Box.java:123)
    at mygame.Box.<init>(Box.java:36)
    at mygame.Main.<init>(Main.java:16)
    at mygame.Main.main(Main.java:69)

Box.java

package mygame;

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.InputStreamReader;

import org.lwjgl.opengl.ARBFragmentShader;
import org.lwjgl.opengl.ARBShaderObjects;
import org.lwjgl.opengl.ARBVertexShader;
import org.lwjgl.opengl.GL11;

/**
* The vertex and fragment shaders are setup when the box object is
* constructed. They are applied to the GL state prior to the box
* being drawn, and released from that state after drawing.
*/
public class Box {

    /*
    * if the shaders are setup ok we can use shaders, otherwise we just
    * use default settings
    */
    private boolean useShader;

    /*
    * program shader, to which is attached a vertex and fragment shaders.
    * They are set to 0 as a check because GL will assign unique int
    * values to each
    */
    private int program=0;

        public Box(){
          int vertShader = 0, fragShader = 0;

          try {
                vertShader = createShader("shaders/screen.vert",ARBVertexShader.GL_VERTEX_SHADER_ARB);
                fragShader = createShader("shaders/screen.frag",ARBFragmentShader.GL_FRAGMENT_SHADER_ARB);
          }
          catch(Exception exc) {
            exc.printStackTrace();
            return;
          }
          finally {
            if(vertShader == 0 || fragShader == 0)
              return;
          }

          program = ARBShaderObjects.glCreateProgramObjectARB();

          if(program == 0)
            return;

            /*
            * if the vertex and fragment shaders setup sucessfully,
            * attach them to the shader program, link the sahder program
            * (into the GL context I suppose), and validate
            */
            ARBShaderObjects.glAttachObjectARB(program, vertShader);
            ARBShaderObjects.glAttachObjectARB(program, fragShader);

            ARBShaderObjects.glLinkProgramARB(program);
            if (ARBShaderObjects.glGetObjectParameteriARB(program, ARBShaderObjects.GL_OBJECT_LINK_STATUS_ARB) == GL11.GL_FALSE) {
                System.err.println(getLogInfo(program));
                return;
            }

            ARBShaderObjects.glValidateProgramARB(program);
            if (ARBShaderObjects.glGetObjectParameteriARB(program, ARBShaderObjects.GL_OBJECT_VALIDATE_STATUS_ARB) == GL11.GL_FALSE) {
              System.err.println(getLogInfo(program));
              return;
            }

            useShader = true;
        }

        /*
        * If the shader was setup succesfully, we use the shader. Otherwise
        * we run normal drawing code.
        */
        public void draw(){
            if(useShader)
                ARBShaderObjects.glUseProgramObjectARB(program);

            GL11.glLoadIdentity();
            GL11.glTranslatef(0.0f, 0.0f, -10.0f);
            GL11.glColor3f(1.0f, 1.0f, 1.0f);//white

            GL11.glBegin(GL11.GL_QUADS);
            GL11.glVertex3f(-1.0f, 1.0f, 0.0f);
            GL11.glVertex3f(1.0f, 1.0f, 0.0f);
            GL11.glVertex3f(1.0f, -1.0f, 0.0f);
            GL11.glVertex3f(-1.0f, -1.0f, 0.0f);
            GL11.glEnd();

            //release the shader
            if(useShader)
              ARBShaderObjects.glUseProgramObjectARB(0);

        }

        /*
        * With the exception of syntax, setting up vertex and fragment shaders
        * is the same.
        * @param the name and path to the vertex shader
        */
        private int createShader(String filename, int shaderType) throws Exception {
          int shader = 0;
          try {
              shader = ARBShaderObjects.glCreateShaderObjectARB(shaderType);

              if(shader == 0)
                return 0;

              ARBShaderObjects.glShaderSourceARB(shader, readFileAsString(filename));
              ARBShaderObjects.glCompileShaderARB(shader);

              if (ARBShaderObjects.glGetObjectParameteriARB(shader, ARBShaderObjects.GL_OBJECT_COMPILE_STATUS_ARB) == GL11.GL_FALSE)
                  throw new RuntimeException("Error creating shader: " + getLogInfo(shader));

              return shader;
          }
          catch(Exception exc) {
            ARBShaderObjects.glDeleteObjectARB(shader);
            throw exc;
          }
        }

        private static String getLogInfo(int obj) {
            return ARBShaderObjects.glGetInfoLogARB(obj, ARBShaderObjects.glGetObjectParameteriARB(obj, ARBShaderObjects.GL_OBJECT_INFO_LOG_LENGTH_ARB));
        }

        private String readFileAsString(String filename) throws Exception {
            StringBuilder source = new StringBuilder();

            FileInputStream in = new FileInputStream(filename);

            Exception exception = null;

            BufferedReader reader;
            try{
                reader = new BufferedReader(new InputStreamReader(in,"UTF-8"));

                Exception innerExc= null;
                try {
                  String line;
                    while((line = reader.readLine()) != null)
                        source.append(line).append('\n');
                }
                catch(Exception exc) {
                  exception = exc;
                }
                finally {
                  try {
                    reader.close();
                  }
                  catch(Exception exc) {
                    if(innerExc == null)
                      innerExc = exc;
                    else
                      exc.printStackTrace();
                  }
                }

                if(innerExc != null)
                  throw innerExc;
            }
            catch(Exception exc) {
              exception = exc;
            }
            finally {
              try {
                in.close();
              }
              catch(Exception exc) {
                if(exception == null)
                  exception = exc;
                else
              exc.printStackTrace();
              }

              if(exception != null)
                throw exception;
            }

            return source.toString();
        }
    }

银幕

varying vec4 vertColor;

void main(){
    gl_FragColor = vertColor;
}

屏幕垂直

不同的颜色

void main(){
    gl_Position = gl_ModelViewProjectionMatrix*gl_Vertex;
    vertColor = vec4(0.6, 0.3, 0.4, 1.0);
}

---

添加了lwjgl标记，因为这个问题显然涉及到这个库。Java对我来说从来没有太多意义，但不应该这样：privateBox=newBox；在Main.init之后才能执行此操作。。。是否在类范围内成功完成而不是无条件完成？这就是构造函数存在的原因。现在，您可以很容易地使try/catch块失败，并且您的代码仍将尝试创建一个框。

void main(){
    gl_Position = gl_ModelViewProjectionMatrix*gl_Vertex;
    vertColor = vec4(0.6, 0.3, 0.4, 1.0);
}