android - 如何解决这个问题：android 中的 java.lang.NumberFormatException？

Question

我正在android中创建一个条形图，但是我的logcat上出现了这些错误，这是什么意思？请建议...

任何人都可以让我知道解决方案吗？

日志猫

10-03 12:39:26.965: W/KeyCharacterMap(524): No keyboard for id 0
10-03 12:39:26.965: W/KeyCharacterMap(524): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
10-03 12:39:45.455: D/AndroidRuntime(524): Shutting down VM
10-03 12:39:45.455: W/dalvikvm(524): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
10-03 12:39:45.475: E/AndroidRuntime(524): FATAL EXCEPTION: main
10-03 12:39:45.475: E/AndroidRuntime(524): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.test_wb/com.example.test_wb.ResultActivity}: java.lang.NumberFormatException: 
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.app.ActivityThread.access$2300(ActivityThread.java:125)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.os.Handler.dispatchMessage(Handler.java:99)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.os.Looper.loop(Looper.java:123)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.app.ActivityThread.main(ActivityThread.java:4627)
10-03 12:39:45.475: E/AndroidRuntime(524):  at java.lang.reflect.Method.invokeNative(Native Method)
10-03 12:39:45.475: E/AndroidRuntime(524):  at java.lang.reflect.Method.invoke(Method.java:521)
10-03 12:39:45.475: E/AndroidRuntime(524):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
10-03 12:39:45.475: E/AndroidRuntime(524):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
10-03 12:39:45.475: E/AndroidRuntime(524):  at dalvik.system.NativeStart.main(Native Method)
10-03 12:39:45.475: E/AndroidRuntime(524): Caused by: java.lang.NumberFormatException: 
10-03 12:39:45.475: E/AndroidRuntime(524):  at org.apache.harmony.luni.util.FloatingPointParser.parseDblImpl(Native Method)
10-03 12:39:45.475: E/AndroidRuntime(524):  at org.apache.harmony.luni.util.FloatingPointParser.parseDouble(FloatingPointParser.java:283)
10-03 12:39:45.475: E/AndroidRuntime(524):  at java.lang.Double.parseDouble(Double.java:287)
10-03 12:39:45.475: E/AndroidRuntime(524):  at com.example.test_wb.ResultActivity.onCreate(ResultActivity.java:40)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
10-03 12:39:45.475: E/AndroidRuntime(524):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
10-03 12:39:45.475: E/AndroidRuntime(524):  ... 11 more

结果活动.java

public class ResultActivity extends Activity 
{   
TextView txt1,txt2;

String a,b;
double x_axis,y_axis;


@Override
public void onCreate(Bundle savedInstanceState)
{   
super.onCreate(savedInstanceState);
setContentView(R.layout.main1);

Bundle extras = getIntent().getExtras();

if(extras != null)
{   
    a = extras.getString("gotonextpageX");
    b = extras.getString("gotonextpageY");

    double x_axis = Double.parseDouble(a); // Type casting
    double y_axis = Double.parseDouble(b); // Type casting

  }
else
{

}

draw();

//txt1 = (TextView)findViewById(R.id.txtVw);
//txt2 = (TextView)findViewById(R.id.txtVw2);
//txt1.setText(x);
//txt2.setText(y);
}

public void draw()
{   

String[] titles = new String[] { "Order's profit of the year", " " };

List<double[]> values = new ArrayList<double[]>();

values.add(new double[] { y_axis });

int[] colors = new int[] { Color.BLACK, Color.WHITE};

XYMultipleSeriesRenderer renderer = buildBarRenderer(colors);
renderer.setOrientation(Orientation.HORIZONTAL);

 setChartSettings(renderer, "Profit for the year 2012", " ", " ",0,x_axis, 0,y_axis, Color.GRAY, Color.LTGRAY);

renderer.setXLabels(1);
renderer.addXTextLabel(100, "x");

//renderer.addXTextLabel(200, "ord2");
//renderer.addXTextLabel(300, "ord3");
//renderer.addXTextLabel(400, "ord4");
//renderer.setPanEnabled(true, false);

int length = renderer.getSeriesRendererCount();

for (int i = 0; i < length; i++) 
{
    SimpleSeriesRenderer seriesRenderer = renderer.getSeriesRendererAt(i);
    seriesRenderer.setDisplayChartValues(true);
    }

ChartFactory.getBarChartIntent(this, buildBarDataset(titles, values), renderer,Type.DEFAULT);
}

protected XYMultipleSeriesRenderer buildBarRenderer(int[] colors) 
{   

  // creates a SeriesRenderer and initializes it with useful default values as well as colors

    XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer();

    renderer.setAxisTitleTextSize(15);
    renderer.setChartTitleTextSize(20);
    renderer.setLabelsTextSize(15);
    renderer.setLegendTextSize(15);

    int length = colors.length;

    for (int i = 0; i < length; i++) 
    {
        SimpleSeriesRenderer r = new SimpleSeriesRenderer();
        r.setColor(colors[i]);
        renderer.addSeriesRenderer(r);
        }
    return renderer;
    }

protected void setChartSettings(XYMultipleSeriesRenderer renderer, String title, String xTitle,
String yTitle, double xMin, double x_axis2, double yMin, double yMax, int axesColor,int labelsColor) 
{   

// sets lots of default values for this renderer

renderer.setChartTitle(title);
renderer.setXTitle(xTitle);
renderer.setYTitle(yTitle);

renderer.setXAxisMin(xMin);

//renderer.setXAxisMax(x2);

renderer.setYAxisMin(yMin);
renderer.setYAxisMax(yMax);

renderer.setAxesColor(axesColor);
renderer.setLabelsColor(labelsColor);

renderer.setApplyBackgroundColor(true);
renderer.setBackgroundColor(Color.GRAY);
}

protected XYMultipleSeriesDataset buildBarDataset(String[] titles, List<double[]> values) 
{   
// adds the axis titles and values into the data-set

XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset();
int length = titles.length;

for (int i = 0; i < length; i++) 
{
    CategorySeries series = new CategorySeries(titles[i]);

    double[] v = values.get(i);
    int seriesLength = v.length;

    for (int k = 0; k < seriesLength; k++) 
    {
        series.add(v[k]);
    }

    dataset.addSeries(series.toXYSeries());
}
return dataset;
}}

Main_WB.java

public class Main_WB extends Activity
{
EditText edt1, edt2;
// TextView txt_1;

Button btn;
ArrayList<String> result;

@Override
public void onCreate(Bundle savedInstanceState) 
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

edt1 = (EditText) findViewById(R.id.editText1);
edt2 = (EditText) findViewById(R.id.editText2);
btn = (Button) findViewById(R.id.button1);

result = new ArrayList<String>();

btn.setOnClickListener(new View.OnClickListener() 
{
    public void onClick(View v) 
    {
        result.addAll(getTMSChart(edt1.getText().toString(), edt2.getText().toString()));

        Intent in = new Intent(getApplicationContext(), ResultActivity.class);

        in.putExtra("gotonextpageX", result.get(0));
        in.putExtra("gotonextpageY", result.get(1));

        startActivity(in);
    }
});
}
private ArrayList<String> getTMSChart(String FromDate, String ToDate) 
{
// txt_1 = (TextView)findViewById(R.id.textView1);

System.setProperty("http.keepAlive", "false");
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);

envelope.dotNet = true;

String NAMESPACE = "http://tempuri.org/";
String URL = "http://54.251.60.177/TMSOrdersService/TMSDetails.asmx";
String METHOD = "GetTMSChart";

SoapObject request = new SoapObject(NAMESPACE, METHOD);
request.addProperty("FromDate", FromDate);
request.addProperty("ToDate", ToDate);

envelope.setOutputSoapObject(request);
HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);

String x = "", y = "";

ArrayList<String> stringResult = new ArrayList<String>();

try 
{
    androidHttpTransport.call(NAMESPACE + METHOD, envelope);
    SoapObject result = (SoapObject) envelope.bodyIn;
    SoapObject root = (SoapObject) ((SoapObject) (result).getProperty(0)).getProperty("NewDataSet");
    int tablesCount = root.getPropertyCount();

    for (int i = 0; i < tablesCount; i++) 
    {
        SoapObject table = (SoapObject) root.getProperty(i);
        int propertyCount = table.getPropertyCount();

        for (int j = 0; j < propertyCount; j++) 
        {

            stringResult.add(table.getPropertyAsString("Order_No").toString());
            stringResult.add(table.getPropertyAsString("Freight_Rate").toString());
        }
    }
}
catch (Exception e) 
{
}

return stringResult;
}}

谢谢你的时间！..

score 0 · Accepted Answer

来自官方文档：

“公共类 NumberFormatException 扩展了 IllegalArgumentException

抛出以表明应用程序已尝试将字符串转换为其中一种数字类型，但该字符串没有适当的格式。”

您可能正在尝试将字符串解析为数字类型（在您的情况下，将字符串解析为双精度类型），但该字符串可能没有正确的格式来转换为双精度类型。

因此，在代码中，当您使用意图对象获取值时，请检查它们的格式是否正确。或者，当您将它们插入到用于调用此活动的意图对象中时，只需正确格式化它们，即 intent.putExtra(...)

score 0 · Accepted Answer

double x_axis = Double.parseDouble(a); // Type casting
double y_axis = Double.parseDouble(b); // Type casting

此处的 a 或 b 都不能转换为 double。也许其中之一为空、空或不是数字？

score 0 · Accepted Answer

您正在尝试将字符串转换为

double x_axis = Double.parseDouble(a); // Type casting
double y_axis = Double.parseDouble(b); // Type casting

成双。现在解析器试图理解输入字符串并且在不属于数字的字符上失败，例如字母'a'。

您可以在进行解析之前打印“a”和“b”的值，以查看它们是什么并修复解析。或者在调试器中启动您的应用程序并在第 40 行放置一个断点。

android - 如何解决这个问题：android 中的 java.lang.NumberFormatException？

3 回答 3

Related

Reference