Initial data commit

Task/Align-columns/Java/align-columns.java

@@ -0,0 +1,144 @@
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.lang3.StringUtils;
+
+/**
+ * Aligns fields into columns, separated by "|"
+ */
+public class ColumnAligner {
+    private List<String[]> words = new ArrayList<>();
+    private int columns = 0;
+    private List<Integer> columnWidths = new ArrayList<>();
+
+    /**
+     * Initialize columns aligner from lines in a single string
+     *
+     * @param s
+     *            lines in a single string. Empty string does form a column.
+     */
+    public ColumnAligner(String s) {
+        String[] lines = s.split("\\n");
+        for (String line : lines) {
+            processInputLine(line);
+        }
+    }
+
+    /**
+     * Initialize columns aligner from lines in a list of strings
+     *
+     * @param lines
+     *            lines in a single string. Empty string does form a column.
+     */
+    public ColumnAligner(List<String> lines) {
+        for (String line : lines) {
+            processInputLine(line);
+        }
+    }
+
+    private void processInputLine(String line) {
+        String[] lineWords = line.split("\\$");
+        words.add(lineWords);
+        columns = Math.max(columns, lineWords.length);
+        for (int i = 0; i < lineWords.length; i++) {
+            String word = lineWords[i];
+            if (i >= columnWidths.size()) {
+                columnWidths.add(word.length());
+            } else {
+                columnWidths.set(i, Math.max(columnWidths.get(i), word.length()));
+            }
+        }
+    }
+
+    interface AlignFunction {
+        String align(String s, int length);
+    }
+
+    /**
+     * Left-align all columns
+     *
+     * @return Lines, terminated by "\n" of columns, separated by "|"
+     */
+    public String alignLeft() {
+        return align(new AlignFunction() {
+            @Override
+            public String align(String s, int length) {
+                return StringUtils.rightPad(s, length);
+            }
+        });
+    }
+
+    /**
+     * Right-align all columns
+     *
+     * @return Lines, terminated by "\n" of columns, separated by "|"
+     */
+    public String alignRight() {
+        return align(new AlignFunction() {
+            @Override
+            public String align(String s, int length) {
+                return StringUtils.leftPad(s, length);
+            }
+        });
+    }
+
+    /**
+     * Center-align all columns
+     *
+     * @return Lines, terminated by "\n" of columns, separated by "|"
+     */
+    public String alignCenter() {
+        return align(new AlignFunction() {
+            @Override
+            public String align(String s, int length) {
+                return StringUtils.center(s, length);
+            }
+        });
+    }
+
+    private String align(AlignFunction a) {
+        StringBuilder result = new StringBuilder();
+        for (String[] lineWords : words) {
+            for (int i = 0; i < lineWords.length; i++) {
+                String word = lineWords[i];
+                if (i == 0) {
+                    result.append("|");
+                }
+                result.append(a.align(word, columnWidths.get(i)) + "|");
+            }
+            result.append("\n");
+        }
+        return result.toString();
+    }
+
+    public static void main(String args[]) throws IOException {
+        if (args.length < 1) {
+            System.out.println("Usage: ColumnAligner file [left|right|center]");
+            return;
+        }
+        String filePath = args[0];
+        String alignment = "left";
+        if (args.length >= 2) {
+            alignment = args[1];
+        }
+        ColumnAligner ca = new ColumnAligner(Files.readAllLines(Paths.get(filePath), StandardCharsets.UTF_8));
+        switch (alignment) {
+        case "left":
+            System.out.print(ca.alignLeft());
+            break;
+        case "right":
+            System.out.print(ca.alignRight());
+            break;
+        case "center":
+            System.out.print(ca.alignCenter());
+            break;
+        default:
+            System.err.println(String.format("Error! Unknown alignment: '%s'", alignment));
+            break;
+        }
+    }
+}