Method Overloading Error- "Editors doesn't contain main type" - methods

package MethodOverloadding;
public class MethodOverloadding {
public static void main(String[] args) {
System.out.println("Area of rectangle: "+area(14.25d, 10.65d));
System.out.println("Area of square: "+area(5.0d));
}
public static double area(double length, double width){
return length*width;
}
public static double area(double side){
return side*side;
}
public static int area(int side){
return side*side;
}
}

Related

trino udf how to create a aggregate function for the window function

I tried to write a udf function to calculate my data. In the trino's docs, I knew I should to write a function plugin and I succeed to execute my udf aggregate function sql.
But when I write sql with aggregate function and window function, the sql executed failed.
The error log is com.google.common.util.concurrent.ExecutionError: java.lang.NoClassDefFoundError: com/example/ListState.
I think I may implement the interface about the window function.
The ListState.java file code
#AccumulatorStateMetadata(stateSerializerClass = ListStateSerializer.class, stateFactoryClass = ListStateFactory.class)
public interface ListState extends AccumulatorState {
List<String> getList();
void setList(List<String> value);
}
The ListStateSerializer file code
public class ListStateSerializer implements AccumulatorStateSerializer<ListState>
{
#Override
public Type getSerializedType() {
return VARCHAR;
}
#Override
public void serialize(ListState state, BlockBuilder out) {
if (state.getList() == null) {
out.appendNull();
return;
}
String value = String.join(",", state.getList());
VARCHAR.writeSlice(out, Slices.utf8Slice(value));
}
#Override
public void deserialize(Block block, int index, ListState state) {
String value = VARCHAR.getSlice(block, index).toStringUtf8();
List<String> list = Arrays.asList(value.split(","));
state.setList(list);
}
}
The ListStateFactory file code
public class ListStateFactory implements AccumulatorStateFactory<ListState> {
public static final class SingleListState implements ListState {
private List<String> list = new ArrayList<>();
#Override
public List<String> getList() {
return list;
}
#Override
public void setList(List<String> value) {
list = value;
}
#Override
public long getEstimatedSize() {
if (list == null) {
return 0;
}
return list.size();
}
}
public static class GroupedListState implements GroupedAccumulatorState, ListState {
private final ObjectBigArray<List<String>> container = new ObjectBigArray<>();
private long groupId;
#Override
public List<String> getList() {
return container.get(groupId);
}
#Override
public void setList(List<String> value) {
container.set(groupId, value);
}
#Override
public void setGroupId(long groupId) {
this.groupId = groupId;
if (this.getList() == null) {
this.setList(new ArrayList<String>());
}
}
#Override
public void ensureCapacity(long size) {
container.ensureCapacity(size);
}
#Override
public long getEstimatedSize() {
return container.sizeOf();
}
}
#Override
public ListState createSingleState() {
return new SingleListState();
}
#Override
public ListState createGroupedState() {
return new GroupedListState();
}
}
Thanks for help!!!!
And I found the WindowAccumulator class in the trino source code. But I don't know how to use it.
How to create a aggregate function for window function?

create an application that prompts the user for a set of five integer numbers using data structure

*Using the ArrayBoundedStack class,create an application named EditNumbers that prompts the user for a set of five integer numbers, push its content into a stack, and then repeatedly prompts the user for changes to numbers, until the user enters an X, indicating the end of changes. Legal change operations are: M, A, R, and C.
• Option M return the maximum value in the set
• Option A v1 means add v1 to each number in the set
• Option R means reverse the numbers in the set
• Option C v1 v2 means change all occurrences of v1 to v2
*
(arrayboundedstack) using this codes bellow
**1)** package stack;
public class ArrayBoundedStack <T> implements StackInterface <T> {
private final int DEFSIZE=100;
private int index=-1;
private T[] arr;
public ArrayBoundedStack()
{
arr=(T[])new Object[DEFSIZE];
}
public ArrayBoundedStack(int size)
{
arr=(T[])new Object[size];
}
public boolean isFull()
{
return index == (arr.length-1);
}
public boolean isEmpty()
{
return index == -1;
}
public void push(T element)
{
if(!isFull())
{
index++;
arr[index]=element;
}
else{
throw new OverflowStackException("The stack is fill , you cannot push");
}
}
public void pop()
{
if(!isEmpty())
{
arr[index]=null;
index--;
}
else{
throw new UnderflowStackException("The stack is empty , you cannot pop");
}
}
public T top()
{
T temp=null;
if (!isEmpty())
temp=arr[index];
else{
throw new UnderflowStackException("The stack is empty , there is no top");
}
return temp;
}
}
**2) ** package stack;
public class MyApp1 {
public static void printStack(ArrayBoundedStack<Integer> st)
{
ArrayBoundedStack<Integer> temp=new ArrayBoundedStack<>(10);
System.out.println("the stack contains:");
while(!st.isEmpty())
{
System.out.println(st.top());
temp.push(st.top());
st.pop();
}
while(!temp.isEmpty())
{
st.push(temp.top());
temp.pop();
}
}
public static void nonNegativeStack(ArrayBoundedStack<Integer> st)
{
ArrayBoundedStack<Integer> temp=new ArrayBoundedStack<>();
while(!st.isEmpty())
{
if(st.top()>=0)
temp.push(st.top());
st.pop();
}
while(!temp.isEmpty())
{
st.push(temp.top());
temp.pop();
}
}
public static void main(String[] args)
{
ArrayBoundedStack<Integer> st=new ArrayBoundedStack<>(10);
st.push(10);
st.push(15);
st.push(30);
printStack(st);
System.out.println("the top of stack is " + st.top());
st.pop();
st.pop();
st.pop();
System.out.println("the top of stack is " + st.top());
}
}
**3) ** package stack;
public class MyApp2 {
public static void main(String[] args)
{
System.out.println("This is a test for exception");
throw new OverflowStackException("the stack is full");
}
}
**4)** package stack;
public class OverflowStackException extends RuntimeException{
public OverflowStackException()
{
super();
}
public OverflowStackException(String msg)
{
super(msg);
}
}
**5) ** package stack;
public interface StackInterface <T> {
public void push(T element) throws OverflowStackException;
public void pop() throws UnderflowStackException;
public T top()throws UnderflowStackException;
public boolean isFull();
public boolean isEmpty();
}
**6)**package stack;
public class UnderflowStackException extends RuntimeException{
public UnderflowStackException()
{
super();
}
public UnderflowStackException(String msg)
{
super(msg);
}
}
i made all the class up and i didnt know how to make a main class

The method clone() from the type Object is not visible

for the life of me I can't figure out what is wrong with this code, please help. I have three classes, GeometricObject, Octagon which extends GeometricObject and TestOctagon which is being used to test the Octagon class. When I run the TestOctagon class I get this error:
The method clone() from the type Object is not visible
Here is my code:
public abstract class GeometricObject {
private String color = "white";
private boolean filled;
protected GeometricObject() {
}
protected GeometricObject(String color, boolean filled) {
this.color = color;
this.filled = filled;
}
public String getColor() {
return color;
}
public void setColor(String color) {
this.color = color;
}
public boolean isFilled() {
return filled;
}
public void setFilled(boolean filled) {
this.filled = filled;
}
public abstract double getArea();
public abstract double getPerimeter();
}
import java.lang.Comparable;
import java.lang.Cloneable;
public class Octagon extends GeometricObject implements Comparable<Octagon>, Cloneable{
double side;
public Octagon() {
}
public Octagon(double side) {
this.side = side;
}
public Octagon(double side, String color, boolean filled) {
this.side = side;
setColor(color);
setFilled(filled);
}
public double getSide() {
return side;
}
public void setSide(double side) {
this.side = side;
}
public double getArea() {
return (2+4/Math.sqrt(2))*side*side;
}
public double getPerimeter() {
return 8*side;
}
#Override
public int compareTo(Octagon o) {
if (getArea() > o.getArea())
return 1;
else if (getArea() < o.getArea())
return -1;
else
return 0;
}
#Override
public Object clone() throws CloneNotSupportedException {
return super.clone();
}
}
public class TestOctagon {
public static void main(String[] args) {
// TODO Auto-generated method stub
GeometricObject oc1 = new Octagon(5);
System.out.println(oc1.getArea());
System.out.println(oc1.getPerimeter());
GeometricObject oc2 = (GeometricObject)oc1.clone();
}
}
Don,
Please note that the access specifier for method Object::clone() is protected. It is not accessible from your TestOctagon class as you are invoking this method on object of type GeometriObject (oc1) where the clone method is still protected as neither it or its super classes have overridden it. Try moving the clone method from Octagon class to GeometriObject class. Please retain the public access specifier. Refer this sample on how to do it http://www.javatpoint.com/object-cloning

Map-Reduce not reducing as much as expected with complex keys and values

No matter how simple I make the compareTo of my complex key, I don't get expected results. With the exception of if I use one key that is the same for every record, it will appropriately reduce to one record. I've also witnessed that this happens only when I process the full load, if I break off a few of the records that didn't reduce and run it on a much smaller scale those records get combined.
The sum of the output records is correct, but there is duplication at the record level of items I would have expected to group together. So where I would expect say 500 records summing up to 5,000, I end up with 1232 records summing up to 5,000 with obvious records that should have been reduced into one.
I've read about the problems with object references and complex keys and values, but I don't see anywhere that I have potential for that left. To that end you will find places that I'm creating new objects that I probably don't need to, but I'm trying everything at this point and will dial it back once it is working.
I'm out of ideas on what to try or where and how to poke to figure this out. Please help!
public static class Map extends
Mapper<LongWritable, Text, IMSTranOut, IMSTranSums> {
//private SimpleDateFormat dtFormat = new SimpleDateFormat("yyyyddd");
#Override
public void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
String line = value.toString();
SimpleDateFormat dtFormat = new SimpleDateFormat("yyyyddd");
IMSTranOut dbKey = new IMSTranOut();
IMSTranSums sumVals = new IMSTranSums();
String[] tokens = line.split(",", -1);
dbKey.setLoadKey(-99);
dbKey.setTranClassKey(-99);
dbKey.setTransactionCode(tokens[0]);
dbKey.setTransactionType(tokens[1]);
dbKey.setNpaNxx(getNPA(dbKey.getTransactionCode()));
try {
dbKey.setTranDate(new Date(dtFormat.parse(tokens[2]).getTime()));
} catch (ParseException e) {
}// 2
dbKey.setTranHour(getTranHour(tokens[3]));
try {
dbKey.setStartDate(new Date(dtFormat.parse(tokens[4]).getTime()));
} catch (ParseException e) {
}// 4
dbKey.setStartHour(getTranHour(tokens[5]));
try {
dbKey.setStopDate(new Date(dtFormat.parse(tokens[6]).getTime()));
} catch (ParseException e) {
}// 6
dbKey.setStopHour(getTranHour(tokens[7]));
sumVals.setTranCount(1);
sumVals.setInputQTime(Double.parseDouble(tokens[8]));
sumVals.setElapsedTime(Double.parseDouble(tokens[9]));
sumVals.setCpuTime(Double.parseDouble(tokens[10]));
context.write(dbKey, sumVals);
}
}
public static class Reduce extends
Reducer<IMSTranOut, IMSTranSums, IMSTranOut, IMSTranSums> {
#Override
public void reduce(IMSTranOut key, Iterable<IMSTranSums> values,
Context context) throws IOException, InterruptedException {
int tranCount = 0;
double inputQ = 0;
double elapsed = 0;
double cpu = 0;
for (IMSTranSums val : values) {
tranCount += val.getTranCount();
inputQ += val.getInputQTime();
elapsed += val.getElapsedTime();
cpu += val.getCpuTime();
}
IMSTranSums sumVals=new IMSTranSums();
IMSTranOut dbKey=new IMSTranOut();
sumVals.setCpuTime(inputQ);
sumVals.setElapsedTime(elapsed);
sumVals.setInputQTime(cpu);
sumVals.setTranCount(tranCount);
dbKey.setLoadKey(key.getLoadKey());
dbKey.setTranClassKey(key.getTranClassKey());
dbKey.setNpaNxx(key.getNpaNxx());
dbKey.setTransactionCode(key.getTransactionCode());
dbKey.setTransactionType(key.getTransactionType());
dbKey.setTranDate(key.getTranDate());
dbKey.setTranHour(key.getTranHour());
dbKey.setStartDate(key.getStartDate());
dbKey.setStartHour(key.getStartHour());
dbKey.setStopDate(key.getStopDate());
dbKey.setStopHour(key.getStopHour());
dbKey.setInputQTime(inputQ);
dbKey.setElapsedTime(elapsed);
dbKey.setCpuTime(cpu);
dbKey.setTranCount(tranCount);
context.write(dbKey, sumVals);
}
}
Here is the implementation of the DBWritable class:
public class IMSTranOut implements DBWritable,
WritableComparable<IMSTranOut> {
private int loadKey;
private int tranClassKey;
private String npaNxx;
private String transactionCode;
private String transactionType;
private Date tranDate;
private double tranHour;
private Date startDate;
private double startHour;
private Date stopDate;
private double stopHour;
private double inputQTime;
private double elapsedTime;
private double cpuTime;
private int tranCount;
public void readFields(ResultSet rs) throws SQLException {
setLoadKey(rs.getInt("LOAD_KEY"));
setTranClassKey(rs.getInt("TRAN_CLASS_KEY"));
setNpaNxx(rs.getString("NPA_NXX"));
setTransactionCode(rs.getString("TRANSACTION_CODE"));
setTransactionType(rs.getString("TRANSACTION_TYPE"));
setTranDate(rs.getDate("TRAN_DATE"));
setTranHour(rs.getInt("TRAN_HOUR"));
setStartDate(rs.getDate("START_DATE"));
setStartHour(rs.getInt("START_HOUR"));
setStopDate(rs.getDate("STOP_DATE"));
setStopHour(rs.getInt("STOP_HOUR"));
setInputQTime(rs.getInt("INPUT_Q_TIME"));
setElapsedTime(rs.getInt("ELAPSED_TIME"));
setCpuTime(rs.getInt("CPU_TIME"));
setTranCount(rs.getInt("TRAN_COUNT"));
}
public void write(PreparedStatement ps) throws SQLException {
ps.setInt(1, loadKey);
ps.setInt(2, tranClassKey);
ps.setString(3, npaNxx);
ps.setString(4, transactionCode);
ps.setString(5, transactionType);
ps.setDate(6, tranDate);
ps.setDouble(7, tranHour);
ps.setDate(8, startDate);
ps.setDouble(9, startHour);
ps.setDate(10, stopDate);
ps.setDouble(11, stopHour);
ps.setDouble(12, inputQTime);
ps.setDouble(13, elapsedTime);
ps.setDouble(14, cpuTime);
ps.setInt(15, tranCount);
}
public int getLoadKey() {
return loadKey;
}
public void setLoadKey(int loadKey) {
this.loadKey = loadKey;
}
public int getTranClassKey() {
return tranClassKey;
}
public void setTranClassKey(int tranClassKey) {
this.tranClassKey = tranClassKey;
}
public String getNpaNxx() {
return npaNxx;
}
public void setNpaNxx(String npaNxx) {
this.npaNxx = new String(npaNxx);
}
public String getTransactionCode() {
return transactionCode;
}
public void setTransactionCode(String transactionCode) {
this.transactionCode = new String(transactionCode);
}
public String getTransactionType() {
return transactionType;
}
public void setTransactionType(String transactionType) {
this.transactionType = new String(transactionType);
}
public Date getTranDate() {
return tranDate;
}
public void setTranDate(Date tranDate) {
this.tranDate = new Date(tranDate.getTime());
}
public double getTranHour() {
return tranHour;
}
public void setTranHour(double tranHour) {
this.tranHour = tranHour;
}
public Date getStartDate() {
return startDate;
}
public void setStartDate(Date startDate) {
this.startDate = new Date(startDate.getTime());
}
public double getStartHour() {
return startHour;
}
public void setStartHour(double startHour) {
this.startHour = startHour;
}
public Date getStopDate() {
return stopDate;
}
public void setStopDate(Date stopDate) {
this.stopDate = new Date(stopDate.getTime());
}
public double getStopHour() {
return stopHour;
}
public void setStopHour(double stopHour) {
this.stopHour = stopHour;
}
public double getInputQTime() {
return inputQTime;
}
public void setInputQTime(double inputQTime) {
this.inputQTime = inputQTime;
}
public double getElapsedTime() {
return elapsedTime;
}
public void setElapsedTime(double elapsedTime) {
this.elapsedTime = elapsedTime;
}
public double getCpuTime() {
return cpuTime;
}
public void setCpuTime(double cpuTime) {
this.cpuTime = cpuTime;
}
public int getTranCount() {
return tranCount;
}
public void setTranCount(int tranCount) {
this.tranCount = tranCount;
}
public void readFields(DataInput input) throws IOException {
setNpaNxx(input.readUTF());
setTransactionCode(input.readUTF());
setTransactionType(input.readUTF());
setTranDate(new Date(input.readLong()));
setStartDate(new Date(input.readLong()));
setStopDate(new Date(input.readLong()));
setLoadKey(input.readInt());
setTranClassKey(input.readInt());
setTranHour(input.readDouble());
setStartHour(input.readDouble());
setStopHour(input.readDouble());
setInputQTime(input.readDouble());
setElapsedTime(input.readDouble());
setCpuTime(input.readDouble());
setTranCount(input.readInt());
}
public void write(DataOutput output) throws IOException {
output.writeUTF(npaNxx);
output.writeUTF(transactionCode);
output.writeUTF(transactionType);
output.writeLong(tranDate.getTime());
output.writeLong(startDate.getTime());
output.writeLong(stopDate.getTime());
output.writeInt(loadKey);
output.writeInt(tranClassKey);
output.writeDouble(tranHour);
output.writeDouble(startHour);
output.writeDouble(stopHour);
output.writeDouble(inputQTime);
output.writeDouble(elapsedTime);
output.writeDouble(cpuTime);
output.writeInt(tranCount);
}
public int compareTo(IMSTranOut o) {
return (Integer.compare(loadKey, o.getLoadKey()) == 0
&& Integer.compare(tranClassKey, o.getTranClassKey()) == 0
&& npaNxx.compareTo(o.getNpaNxx()) == 0
&& transactionCode.compareTo(o.getTransactionCode()) == 0
&& (transactionType.compareTo(o.getTransactionType()) == 0)
&& tranDate.compareTo(o.getTranDate()) == 0
&& Double.compare(tranHour, o.getTranHour()) == 0
&& startDate.compareTo(o.getStartDate()) == 0
&& Double.compare(startHour, o.getStartHour()) == 0
&& stopDate.compareTo(o.getStopDate()) == 0
&& Double.compare(stopHour, o.getStopHour()) == 0) ? 0 : 1;
}
}
Implementation of the Writable class for the complex values:
public class IMSTranSums
implements Writable{
private double inputQTime;
private double elapsedTime;
private double cpuTime;
private int tranCount;
public double getInputQTime() {
return inputQTime;
}
public void setInputQTime(double inputQTime) {
this.inputQTime = inputQTime;
}
public double getElapsedTime() {
return elapsedTime;
}
public void setElapsedTime(double elapsedTime) {
this.elapsedTime = elapsedTime;
}
public double getCpuTime() {
return cpuTime;
}
public void setCpuTime(double cpuTime) {
this.cpuTime = cpuTime;
}
public int getTranCount() {
return tranCount;
}
public void setTranCount(int tranCount) {
this.tranCount = tranCount;
}
public void write(DataOutput output) throws IOException {
output.writeDouble(inputQTime);
output.writeDouble(elapsedTime);
output.writeDouble(cpuTime);
output.writeInt(tranCount);
}
public void readFields(DataInput input) throws IOException {
inputQTime=input.readDouble();
elapsedTime=input.readDouble();
cpuTime=input.readDouble();
tranCount=input.readInt();
}
}
Your compareTo is flawed, it will totally fail the sort algorithm, because you seem to break transivity in your ordering.
I would recommend you to use a CompareToBuilder from Apache Commons or a ComparisonChain from Guava to make your comparisons much more readable (and correct!).

Invalid void error and illegal modifier error

I keep getting this error:
Illegal modifier for the local class myWebClient; only abstract or final is permitted.
and this error:
void is an invalid type for the variable backButtonClicked
Heres the code where the error occurs.
public class myWebClient extends WebViewClient
{
}
public void backButtonClicked(View view)
{
if (ourBrow.canGoBack())
ourBrow.goBack();
}
public void forwardButtonClicked(View view)
{
if (ourBrow.canGoForward())
ourBrow.goForward();
}
public void goButtonClicked(View view)
{
String theWebsite = Url.getText().toString();
if(theWebsite != null)
ourBrow.loadUrl(theWebsite);
}
public void refreshButtonClicked(View view)
{
ourBrow.reload();
}
Remove the public modifier of the class and put all methods inside the body of the class:
class myWebClient extends WebViewClient
{
public void backButtonClicked(View view)
{
if (ourBrow.canGoBack())
ourBrow.goBack();
}
public void forwardButtonClicked(View view)
{
if (ourBrow.canGoForward())
ourBrow.goForward();
}
public void goButtonClicked(View view)
{
String theWebsite = Url.getText().toString();
if(theWebsite != null)
ourBrow.loadUrl(theWebsite);
}
public void refreshButtonClicked(View view)
{
ourBrow.reload();
}
}

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