差分

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--- programming:java [2013/08/20 02:17] – dot
+++ programming:java [2015/06/17 05:20] (現在) – 外部編集 127.0.0.1
@@ 行 23: / 行 23: @@
     public static void main(String args[]){
         System.out.println(ToStringBuilder.reflectionToString(args));
+    }
+}
+</file>
+===== ファイル入出力 =====
+<file java FileInputOutput.java>
+import java.io.FileInputStream;
+import java.io.InputStreamReader;
+import java.io.BufferedReader;
+import java.io.FileOutputStream;
+import java.io.OutputStreamWriter;
+import java.io.BufferedWriter;
+import java.io.PrintWriter;
+import java.io.IOException;
+public class FileInputOutput {
+    public static void main(String[] args) {
+        try {
+            String input = "unko.txt";
+            String inputEncoding = "UTF-8";
+            String output = "unko2.txt";
+            String outputEncoding = "UTF-8";
+            BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(input), inputEncoding));
+            PrintWriter pw = new PrintWriter(new BufferedWriter(new OutputStreamWriter(new FileOutputStream(output), outputEncoding)));
+            String line = "";
+            while ((line = br.readLine()) != null) {
+                pw.println(line);
+            }
+            br.close();
+            pw.close();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
     }
 }
@@ 行 48: / 行 87: @@
 }
 </file>
 <file ini application.ini>
@@ 行 55: / 行 93: @@
 </file>
+===== XPathでXMLの読み込み =====
+<file java UseXPath.java>
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+import org.xml.sax.InputSource;
+public class UseXPath{
+    public static void main(String args[]){
+        XPath xpath = XPathFactory.newInstance().newXPath();
+        InputSource inputSource = new InputSource("test.xml");
+        String expression = "//test/unko[@id='hello']";
+        try {
+            NodeList nodes = (NodeList) xpath.evaluate(expression, inputSource, XPathConstants.NODESET);
+            for (int i = 0; i < nodes.getLength(); i++) {
+                Node node = nodes.item(i);
+                String str = node.getTextContent();
+                System.out.println(str);
+            }
+        } catch (XPathExpressionException e) {
+            e.printStackTrace();
+        }
+    }
+}
+</file>
+<file xml test.xml>
+<?xml version="1.0" encoding="UTF-8"?>
+<test>
+  <unko id="hello">001</unko>
+  <unko id="world">002</unko>
+</test>
+</file>
+===== 正規表現を用いたパターンマッチ =====
+<file java RegexPatternMatch.java>
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+public class RegexPatternMatch{
+    public static void main(String[] args) {
+        String str = "Hello, World";
+        Matcher matcher = Pattern.compile("(.+?), (.+?)$").matcher(str);
+        if (matcher.find()){
+            System.out.println(matcher.group(1)); //Hello
+            System.out.println(matcher.group(2)); //World
+        }
+    }
+}
+</file>
+===== 正規表現を用いた文字列置換 =====
+<file java RegexReplaceString.java>
+import java.util.regex.Pattern;
+public class RegexReplaceString{
+    public static void main(String[] args) {
+        String str = "Hello, unko";
+        // unko -> World
+        System.out.println(Pattern.compile("(unko)$").matcher(str).replaceFirst("World"));
+        // unko -> World
+        System.out.println(str.replaceAll("(unko)$", "World"));
+    }
+}
+</file>
 ===== 拡張子指定ファイル一覧 =====
@@ 行 123: / 行 239: @@
 }
 </file>
+===== 型変換 =====
+<file java TypeCast.java>
+public class TypeCast {
+    public static void main(String args[]){
+        int intType = 10;
+        String stringType = "10";
+        // int -> String
+        String a = Integer.toString(intType);
+        // String -> int
+        int b = Integer.parseInt(stringType);
+    }
+}
+</file>