Need help to check on this calculator app building in adroidstudio

Multiplication button not working

Here is my code below :-

MainActivity.java

package com.kean.calculator; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.TextView; public class MainActivity extends AppCompatActivity { private TextView mNumberDisplay; private SimpleExpression mExpression; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my); mNumberDisplay = (TextView) findViewById(R.id.textView1); mExpression = new SimpleExpression(); } public void goAC (View view){ mNumberDisplay.setText(R.string.zero); mExpression.clearOperands(); } public void goOperand (View view) { String val= (String) mNumberDisplay.getText(); String digit = (String) view.getContentDescription(); if (val.charAt(0) == '0') mNumberDisplay.setText(digit); else  mNumberDisplay.setText(mNumberDisplay.getText() + digit); } public void goOperator (View view){ String operator = (String) view.getContentDescription(); String val = (String) mNumberDisplay.getText(); mExpression.setOperand1(Integer.parseInt(val)); mExpression.setOperator(operator); mNumberDisplay.setText(R.string.zero); } public void goCompute (View view){ String val = (String) mNumberDisplay.getText(); mExpression.setOperand2(Integer.parseInt(val)); mNumberDisplay.setText(mExpression.getValue().toString()); } } 

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Simple Expression.java

package com.kean.calculator; /**  * Created by ademola on 11/21/17.  */  public class SimpleExpression { private int mOperand1; private int mOperand2; private String mOperator; private int mResult; public SimpleExpression(){ mOperand1 = 0; mOperand2 = 0; mOperator = "+"; mResult = 0; } public void clearOperands(){ mOperand1 = 0; mOperand2 = 0; } public void setOperand1 (int v){ mOperand1 = v; } public void setOperand2 (int v){ mOperand2 =v; } public void setOperator (String s){ mOperator = s; } public Integer getValue(){ computeValue(); return mResult; } private void computeValue(){ mResult = 0; if (mOperator.contentEquals("+")) mResult = mOperand1 + mOperand2; else if (mOperator.contentEquals("-")) mResult = mOperand1 - mOperand2; else if (mOperator.contentEquals("*")) mResult = mOperand1 * mOperand2; else if (mOperator.contentEquals("/") && mOperand2 != 0) mResult = mOperand1 / mOperand2; else  mResult = mOperand1 % mOperand2; } } 

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xml version="1.0" encoding="utf-8"?> <TableLayout xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:stretchColumns="0,1,2,3"> <TableRow  android:id="@+id/tableRow1"  android:layout_width="match_parent"  android:layout_height="match_parent"> <TextView  android:id="@+id/textView1"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_span="4"  android:background="@color/orange_cream"  android:gravity="right"  android:text="0"  android:textSize="70sp"/> TableRow> <TableRow  android:id="@+id/tableRow2"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:minHeight="7dp"> <Button  android:id="@+id/buttonAC"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:layout_span="2"  android:background="@color/blue_dust"  android:contentDescription="@string/ac"  android:minHeight="70dp"  android:onClick="goAC"  android:text="@string/ac" /> <Button  android:id="@+id/buttonPer"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/percent"  android:minHeight="70dp"  android:onClick="goOperator"  android:text="@string/percent" /> <Button  android:id="@+id/buttonDiv"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/div"  android:minHeight="70dp"  android:onClick="goOperator"  android:text="@string/div" /> TableRow> <TableRow  android:id="@+id/tableRow3"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:minHeight="70dp"> <Button  android:id="@+id/button7"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/seven"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/seven" /> <Button  android:id="@+id/button8"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/eight"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/eight" /> <Button  android:id="@+id/button9"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/nine"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/nine" /> <Button  android:id="@+id/buttonMult"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/mult"  android:minHeight="70dp"  android:onClick="goOperator"  android:text="@string/mult"/> TableRow> <TableRow  android:id="@+id/tableRow4"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:minHeight="70dp"> <Button  android:id="@+id/button4"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/four"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/four" /> <Button  android:id="@+id/button5"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/five"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/five" /> <Button  android:id="@+id/button6"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/six"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/six" /> <Button  android:id="@+id/buttonSub"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/subtract"  android:minHeight="70dp"  android:onClick="goOperator"  android:text="@string/subtract" /> TableRow> <TableRow  android:id="@+id/tableRow5"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:minHeight="70dp"> <Button  android:id="@+id/button1"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/one"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/one" /> <Button  android:id="@+id/button2"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/two"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/two" /> <Button  android:id="@+id/button3"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/three"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/three" /> <Button  android:id="@+id/buttonAdd"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:background="@color/gray"  android:contentDescription="@string/add"  android:minHeight="70dp"  android:onClick="goOperator"  android:text="@string/add" /> TableRow> <TableRow  android:id="@+id/tableRow6"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:minHeight="70dp"> <Button  android:id="@+id/button0"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:layout_span="2"  android:background="@color/gray"  android:contentDescription="@string/zero"  android:minHeight="70dp"  android:onClick="goOperand"  android:text="@string/zero" /> <Button  android:id="@+id/buttonEq"  android:layout_width="wrap_content"  android:layout_height="wrap_content"  android:layout_margin="2dp"  android:layout_span="2"  android:background="@color/blue_dust"  android:contentDescription="@string/equal"  android:minHeight="70dp"  android:onClick="goCompute"  android:text="@string/equal" /> TableRow> TableLayout>