Java C - 1
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InputStream
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SequenceInputStream
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ByteArrayInputStream
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Java C - 3
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Java C - 4
import java.io.*;
OutputStream
FileOutputStream
PipedOutputStream
ByteArrayOutputStream
final class Kopiera
{
public static void main(String[] argument)
{
try
{
FileInputStream orginal =
new FileInputStream(argument[0]);
FileOutputStream kopia =
new FileOutputStream(argument[1]);
int tecken = 0;
while ((tecken = original.read()) != -1)
kopia.write(tecken);
FilterOutputStream
orginal.close();
kopia.close();
DataOutputStream
}
catch (FileNotFoundException fel)
{
System.err.println("Kan inte hitta filen: "
+ argument[0]);
}
catch (IOException fel)
{
System.err.println("I/O-fel:"
+ fel.getMessage());
}
catch (ArrayIndexOutOfBoundsException fel)
{
System.err.println("Använd:
<java Kopiera frånFil tillFil>");
}
PrintStream
BufferedOutputStream
}
}
==> cat > orginalet.txt
Detta är en textfil
<ctrl-D>
==> java Kopiera orginalet.txt kopia.txt
==> cat kopia.txt
Detta är en textfil
==>
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Java C - 5
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Java C - 6
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import java.io.*;
import java.io.*;
final class Kopiera
{
public static void main(String[] argument)
{
try
{
BufferedInputStream orginal =
new BufferedInputStream(
new FileInputStream(argument[0]));
final class WriteRead
{
static void main(String[] argument) throws IOException
{
int helTal = 7;
double decimalTal = Math.PI;
DataOutputStream tillFil = new DataOutputStream(
new BufferedOutputStream(
new FileOutputStream("tal.dat")));
tillFil.writeInt(helTal);
tillFil.writeDouble(decimalTal);
BufferedOutputStream kopia =
new BufferedOutputStream(
new FileOutputStream(argument[1]));
tillFil.close();
// Fortsättningen är lika som i föregående
// exempel
DataInputStream frånFil = new DataInputStream(
new BufferedInputStream(
new FileInputStream("tal.dat")));
System.out.println(frånFil.readInt());
System.out.println(frånFil.readDouble());
frånFil.close();
}
}
==>java WriteRead
7
3.141592653589793
==>jobb>cat tal.dat
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import java.io.*;
public class Spara
{
static Person kalle;
static ObjectOutputStream tillFil;
public static void main(String[] arg) throws Exception
{
kalle = new Person("Kalle", "Röd");
tillFil = new ObjectOutputStream(
new BufferedOutputStream(
new FileOutputStream("person.dat")));
import java.io.*;
public class Cykel implements Serializable
{
private String färg;
public Cykel(String färgen)
{
färg = färgen;
}
public String getFärg()
{
return färg;
}
}
import java.io.*;
tillFil.writeObject(kalle);
tillFil.close();
}
}
import java.io.*;
public class Skapa
{
static Person anonym;
static ObjectInputStream frånFil;
public static void main(String[] arg) throws Exception
{
frånFil = new ObjectInputStream(
new BufferedInputStream(
new FileInputStream("person.dat")));
public class Person implements Serializable
{
private String namn;
private Cykel cykeln;
public Person(String namnet, String färgen)
{
namn = namnet;
cykeln = new Cykel(färgen);
}
public String toString()
{
return namn + " äger en " + cykeln.getFärg() + " cykel";
}
}
Java C - 8
anonym = (Person)frånFil.readObject();
frånFil.close();
System.out.println(anonym);
}
}
Utskrift
Kalle äger en Röd cykel
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Java C - 9
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Reader
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Writer
PipedReader
InputStreamReader
Java C - 10
OutputStreamWriter
BufferedWriter
CharArrayReader
FileReader
FileWriter
BufferedReader
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PipedWriter
FilterWriter
CharArrayWriter
StringReader
LineNumberReader
PrintWriter
PushbackReader
StringWriter
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Java C - 12
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import java.io.*;
final class Kopiera
{
public static void main(String[] arg)
throws Exception
{
BufferedReader orginal = new BufferedReader
(new FileReader(argument[0]));
BufferedWriter kopia = new BufferedWriter
(new FileWriter(argument[1]));
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int tecken = 0;
import java.io.*;
while ((tecken = orginal.read()) != -1)
kopia.write(tecken);
final class Kopiera
{
public static void main(String[] argument)
throws Exception
{
BufferedReader orginal =
new BufferedReader(
new FileReader(argument[0]));
orginal.close();
kopia.close();
}
}
PrintWriter kopia =
new PrintWriter(
new BufferedWriter(
new FileWriter(argument[1])));
String rad = null;
==> cat > orginalet.txt
Detta är en textfil
<ctrl-D>
==> java Kopiera orginalet.txt kopia.txt
==> cat kopia.txt
Detta är en textfil
==>
while ((rad = orginal.readLine()) != null)
kopia.println(rad);
orginal.close();
kopia.close();
}
}
Java C - 13
Java C - 14
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java.lang
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System.in
System.out
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System.out
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System.in
(InputStream) (InputStreamReader)
MinaInData
(BufferedReader)
BufferedReader MinaInData =
new BufferedReader(
new InputStreamReader(System.in));
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readLine
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Java C - 15
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import java.io.*;
final class Eko
{
public static void main(String[] argument)
throws Exception
{
BufferedReader orginal =
new BufferedReader(
new InputStreamReader(System.in));
PrintStream kopia = System.out;
String rad = null;
while ((rad = orginal.readLine()) != null)
kopia.println(rad);
Java C - 16
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PrintStream(OutputStream out),
PrintStream(OutputStream out, boolean autoFlush)
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print(Object), print(String), print(char[]),
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print(double), print(bolean)
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System.out.print(”Vad heter du: ”);
System.out.flush();
orginal.close();
kopia.close();
}
}
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flush
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Java C - 17
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Java C - 18
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import java.io.*;
import java.util.*;
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public final class Adderare
{
public static void main(String[] arg) throws Exception
{
BufferedReader tangentBord =
new BufferedReader(
new InputStreamReader(System.in));
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System.out.print("Ge mig några tal: ");
System.out.flush();
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String rad = tangentBord.readLine();
StringTokenizer ordSeparator =
new StringTokenizer(rad, " \t");
string ord = "1056";
double summan = 0.0;
int heltalet = Integer.parseInt(ord);
while (ordSeparator.hasMoreTokens())
{
String ettOrd = ordSeparator.nextToken();
double ettTal = Double.parseDouble(ettOrd);
summan += ettTal;
}
System.out.println("Summan blir: " + summan);
}
}
