我有以下代码可以给出rdf结果......但是我遇到了无法找到方法的问题.....
package corese;
import static org.junit.Assert.assertEquals;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import com.corese.andro.R;
import fr.inria.acacia.corese.api.IDatatype;
import fr.inria.acacia.corese.exceptions.EngineException;
import fr.inria.edelweiss.kgram.core.Mappings;
import fr.inria.edelweiss.kgraph.core.Graph;
import fr.inria.edelweiss.kgraph.query.QueryProcess;
import fr.inria.edelweiss.kgtool.load.Load;
import fr.inria.edelweiss.kgtool.print.RDFFormat;
import fr.inria.edelweiss.kgtool.print.ResultFormat;
public class andro extends Activity implements View.OnClickListener{
/** Called when the activity is first created. */
Graph graph;
Load ld;
Mappings map;
QueryProcess exec;
ResultFormat f;
RDFFormat f3;
Button runbtn;
Button clearbtn;
Button test;
Button triple;
EditText et1;
TextView tv1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.query);
clearbtn = (Button) findViewById(R.id.clear) ;
runbtn = (Button) findViewById(R.id.run);
test = (Button) findViewById(R.id.test);
triple = (Button) findViewById(R.id.rdf);
tv1 = (TextView) findViewById(R.id.output);
et1 = (EditText) findViewById(R.id.input);
clearbtn.setOnClickListener(new OnClickListener(){
public void onClick(View v){
et1.setText("");
tv1.setText("");
}
});
test.setOnClickListener(new OnClickListener(){
//runbtn.setOnClickListener(new OnClickListener(){
public void onClick(View v){
/* String op = et1.getText().toString();
tv1.setText(op);
*/
// graph = Graph.create();
graph = Graph.create(true);
ld = Load.create(graph);
ld.load("/path/Roy/Home/DownLoad/foaf.rdf");
// ld.load("dataset.rdf");
/*
try {
ld.loadWE("dataset.rdf");
} catch (LoadException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
*/
// String query = null;
Mappings map = null;
String query1 = "select more * (kg:similarity() as ?sim) where {" +
"?x rdf:type c:Engineer " +
"?x c:hasCreated ?doc " +
"?doc rdf:type c:WebPage" +
"}" +
"order by desc(?sim)";
exec = QueryProcess.create(graph);
query1 = et1.getText().toString();
try {
map = exec.query(query1);
IDatatype dt = getValue(map, "?sim");
double sim = dt.getDoubleValue();
assertEquals("Result", sim, .84, 1e-2);
} catch (EngineException e) {
// TODO Auto-generated catch block
assertEquals("Result", true, e);
e.printStackTrace();
}
f = ResultFormat.create(map);
// f3 = TripleFormat.create(map);
String f2 = f.toString();
tv1.setText(f2);
// System.out.println(f);
}
});
}
protected IDatatype getValue(Mappings map2, String string) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
}
}
错误
05-14 09:50:47.364: I/dalvikvm(798): Could not find method org.junit.Assert.assertEquals, referenced from method corese.andro$2.onClick
05-14 09:50:47.364: W/dalvikvm(798): VFY: unable to resolve static method 10020: Lorg/junit/Assert;.assertEquals (Ljava/lang/String;DDD)V
05-14 09:50:47.364: D/dalvikvm(798): VFY: replacing opcode 0x77 at 0x0059
05-14 09:50:47.364: I/dalvikvm(798): Could not find method org.junit.Assert.assertEquals, referenced from method corese.andro$2.onClick
05-14 09:50:47.364: W/dalvikvm(798): VFY: unable to resolve static method 10022: Lorg/junit/Assert;.assertEquals (Ljava/lang/String;Ljava/lang/Object;Ljava/lang/Object;)V
05-14 09:50:47.364: D/dalvikvm(798): VFY: replacing opcode 0x71 at 0x007b
05-14 09:50:47.364: D/dalvikvm(798): VFY: dead code 0x005c-0073 in Lcorese/andro$2;.onClick (Landroid/view/View;)V
05-14 09:50:47.374: D/dalvikvm(798): VFY: dead code 0x007e-0081 in Lcorese/andro$2;.onClick (Landroid/view/View;)V
05-14 09:50:49.004: W/System.err(798): log4j:WARN No appenders could be found for logger (fr.inria.edelweiss.kgtool.load.Load).
05-14 09:50:49.004: W/System.err(798): log4j:WARN Please initialize the log4j system properly.
05-14 09:50:49.004: W/System.err(798): log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
05-14 09:50:49.104: D/AndroidRuntime(798): Shutting down VM
05-14 09:50:49.104: W/dalvikvm(798): threadid=1: thread exiting with uncaught exception (group=0x40015560)
05-14 09:50:49.104: E/AndroidRuntime(798): FATAL EXCEPTION: main
05-14 09:50:49.104: E/AndroidRuntime(798): java.lang.NullPointerException
05-14 09:50:49.104: E/AndroidRuntime(798): at corese.andro$2.onClick(andro.java:101)
05-14 09:50:49.104: E/AndroidRuntime(798): at android.view.View.performClick(View.java:2485)
05-14 09:50:49.104: E/AndroidRuntime(798): at android.view.View$PerformClick.run(View.java:9080)
05-14 09:50:49.104: E/AndroidRuntime(798): at android.os.Handler.handleCallback(Handler.java:587)
05-14 09:50:49.104: E/AndroidRuntime(798): at android.os.Handler.dispatchMessage(Handler.java:92)
05-14 09:50:49.104: E/AndroidRuntime(798): at android.os.Looper.loop(Looper.java:130)
05-14 09:50:49.104: E/AndroidRuntime(798): at android.app.ActivityThread.main(ActivityThread.java:3683)
05-14 09:50:49.104: E/AndroidRuntime(798): at java.lang.reflect.Method.invokeNative(Native Method)
05-14 09:50:49.104: E/AndroidRuntime(798): at java.lang.reflect.Method.invoke(Method.java:507)
05-14 09:50:49.104: E/AndroidRuntime(798): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
05-14 09:50:49.104: E/AndroidRuntime(798): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
05-14 09:50:49.104: E/AndroidRuntime(798): at dalvik.system.NativeStart.main(Native Method)
有人可以解决为什么错误来“无法找到方法org.junit.Assert.assertEquals .....”???
答案 0 :(得分：0)
您的代码中似乎有两个问题：
libs的文件夹中，并且该库位于类路径中有些东西在第101行抛出了NullPointer异常。我怀疑
IDatatype dt = getValue(map, "?sim");
返回null，因此下一行
double sim = dt.getDoubleValue();
正在抛出错误。