SQOOP-2853: Sqoop2: Refactor TableDisplayer to be used in document generation

(Jarek Jarcec Cecho via Abraham Fine)

shell/src/main/java/org/apache/sqoop/shell/ShellEnvironment.java

@@ -21,12 +21,14 @@
 import org.apache.sqoop.common.SqoopException;
 import org.apache.sqoop.shell.core.ShellError;
 import org.apache.sqoop.shell.core.Constants;
+import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.codehaus.groovy.tools.shell.IO;
 
 import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.text.MessageFormat;
+import java.util.List;
 import java.util.Locale;
 import java.util.ResourceBundle;
 
@@ -57,6 +59,18 @@ private ShellEnvironment() {
   private static boolean interactive = false;
   private static long pollTimeout = DEFAULT_POLL_TIMEOUT;
 
+  private static TableDisplayer tableDisplayer = new TableDisplayer(new TableDisplayer.TableDisplayerWriter() {
+    @Override
+    public void append(String text) {
+      print(text);
+    }
+
+    @Override
+    public void newLineAndFlush() {
+      println();
+    }
+  }, TableDisplayer.DEFAULT_STYLE);
+
   static ResourceBundle resource = ResourceBundle.getBundle(Constants.RESOURCE_NAME, Locale.getDefault());
   static SqoopClient client = new SqoopClient(getServerUrl());
   static IO io;
@@ -226,6 +240,10 @@ public static void print(String format, Object... args) {
     io.out.printf(format, args);
   }
 
+  public static void displayTable(List<String> headers, List<String> ...columns) {
+    tableDisplayer.display(headers, columns);
+  }
+
   // for tests only
   public static void cleanup() {
     serverHost = DEFAULT_SERVER_HOST;

shell/src/main/java/org/apache/sqoop/shell/ShowConnectorFunction.java

@@ -27,7 +27,6 @@
 import org.apache.sqoop.common.SqoopException;
 import org.apache.sqoop.model.MConnector;
 import org.apache.sqoop.shell.core.Constants;
-import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.apache.sqoop.validation.Status;
 
 import static org.apache.sqoop.shell.ShellEnvironment.*;
@@ -83,7 +82,7 @@ private void showSummary() {
       supportedDirections.add(connector.getSupportedDirections().toString());
     }
 
-    TableDisplayer.display(header, uniqueNames, versions, classes, supportedDirections);
+    displayTable(header, uniqueNames, versions, classes, supportedDirections);
   }
 
   private void showConnectors() {

shell/src/main/java/org/apache/sqoop/shell/ShowJobFunction.java

@@ -19,12 +19,8 @@
 
 import org.apache.commons.cli.CommandLine;
 import org.apache.commons.cli.OptionBuilder;
-import org.apache.sqoop.common.Direction;
-import org.apache.sqoop.model.MConnector;
 import org.apache.sqoop.model.MJob;
-import org.apache.sqoop.model.MLink;
 import org.apache.sqoop.shell.core.Constants;
-import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.apache.sqoop.validation.Status;
 
 import java.text.DateFormat;
@@ -97,7 +93,7 @@ private void showSummary() {
       availabilities.add(String.valueOf(job.getEnabled()));
     }
 
-    TableDisplayer.display(header, ids, names, fromConnectors, toConnectors, availabilities);
+    displayTable(header, ids, names, fromConnectors, toConnectors, availabilities);
   }
 
   private void showJobs(String jArg) {

shell/src/main/java/org/apache/sqoop/shell/ShowLinkFunction.java

@@ -19,19 +19,13 @@
 
 import org.apache.commons.cli.CommandLine;
 import org.apache.commons.cli.OptionBuilder;
-import org.apache.sqoop.common.SqoopException;
-import org.apache.sqoop.model.MConnector;
 import org.apache.sqoop.model.MLink;
 import org.apache.sqoop.shell.core.Constants;
-import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.apache.sqoop.validation.Status;
 
 import java.text.DateFormat;
-import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
-import java.util.Map;
 
 import static org.apache.sqoop.shell.ShellEnvironment.*;
 import static org.apache.sqoop.shell.utils.ConfigDisplayer.*;
@@ -86,7 +80,7 @@ private void showSummary() {
       availabilities.add(String.valueOf(link.getEnabled()));
     }
 
-    TableDisplayer.display(header, names, connectorNames, availabilities);
+    displayTable(header, names, connectorNames, availabilities);
   }
 
   private void showLinks() {

shell/src/main/java/org/apache/sqoop/shell/ShowPrincipalFunction.java

@@ -22,13 +22,13 @@
 import org.apache.sqoop.model.MPrincipal;
 import org.apache.sqoop.model.MRole;
 import org.apache.sqoop.shell.core.Constants;
-import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.apache.sqoop.validation.Status;
 
 import java.util.LinkedList;
 import java.util.List;
 
 import static org.apache.sqoop.shell.ShellEnvironment.client;
+import static org.apache.sqoop.shell.ShellEnvironment.displayTable;
 import static org.apache.sqoop.shell.ShellEnvironment.resourceString;
 
 @SuppressWarnings("serial")
@@ -70,6 +70,6 @@ private void showPrincipals(MRole role) {
       types.add(principal.getType());
     }
 
-    TableDisplayer.display(header, names, types);
+    displayTable(header, names, types);
   }
 }

shell/src/main/java/org/apache/sqoop/shell/ShowPrivilegeFunction.java

@@ -25,13 +25,13 @@
 import org.apache.sqoop.model.MResource;
 import org.apache.sqoop.shell.core.Constants;
 import org.apache.sqoop.shell.core.ShellError;
-import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.apache.sqoop.validation.Status;
 
 import java.util.LinkedList;
 import java.util.List;
 
 import static org.apache.sqoop.shell.ShellEnvironment.client;
+import static org.apache.sqoop.shell.ShellEnvironment.displayTable;
 import static org.apache.sqoop.shell.ShellEnvironment.resourceString;
 
 @SuppressWarnings("serial")
@@ -108,6 +108,6 @@ private void showPrivileges(MPrincipal principal, MResource resource) {
       withGrant.add(Boolean.toString(privilege.isWith_grant_option()));
     }
 
-    TableDisplayer.display(header, actions, resourceNames, resourceTypes, withGrant);
+    displayTable(header, actions, resourceNames, resourceTypes, withGrant);
   }
 }

shell/src/main/java/org/apache/sqoop/shell/ShowRoleFunction.java

@@ -24,13 +24,13 @@
 import org.apache.sqoop.model.MRole;
 import org.apache.sqoop.shell.core.Constants;
 import org.apache.sqoop.shell.core.ShellError;
-import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.apache.sqoop.validation.Status;
 
 import java.util.LinkedList;
 import java.util.List;
 
 import static org.apache.sqoop.shell.ShellEnvironment.client;
+import static org.apache.sqoop.shell.ShellEnvironment.displayTable;
 import static org.apache.sqoop.shell.ShellEnvironment.resourceString;
 
 @SuppressWarnings("serial")
@@ -83,6 +83,6 @@ private void showRoles(MPrincipal principal) {
       names.add(role.getName());
     }
 
-    TableDisplayer.display(header, names);
+    displayTable(header, names);
   }
 }

shell/src/main/java/org/apache/sqoop/shell/ShowSubmissionFunction.java

@@ -25,7 +25,6 @@
 import org.apache.sqoop.model.MSubmission;
 import org.apache.sqoop.shell.core.Constants;
 import org.apache.sqoop.shell.utils.SubmissionDisplayer;
-import org.apache.sqoop.shell.utils.TableDisplayer;
 import org.apache.sqoop.validation.Status;
 
 import static org.apache.sqoop.shell.ShellEnvironment.*;
@@ -91,7 +90,7 @@ private void showSummary(String jArg) {
       dates.add(submission.getLastUpdateDate().toString());
     }
 
-    TableDisplayer.display(header, jnames, eids, status, dates);
+    displayTable(header, jnames, eids, status, dates);
   }
 
   private void showSubmissions(String jArg) {

shell/src/main/java/org/apache/sqoop/shell/utils/TableDisplayer.java

@@ -22,62 +22,154 @@
 import java.util.LinkedList;
 import java.util.List;
 
-import static org.apache.sqoop.shell.ShellEnvironment.*;
-
 /**
  * Display table based data
  */
 public class TableDisplayer {
 
+  public static class Style {
+    // Various characters that should be used to "draw" the table's columns, lines, ...
+    String headerLineSeparator;
+    String lineSeparator;
+    boolean linesAfterEachRow;
+
+    // Generated ones
+    String columnLeft;
+    String columnRight;
+    String columnMiddle;
+
+    String lineLeft;
+    String lineRight;
+    String lineMiddle;
+
+    String headerLeft;
+    String headerRight;
+    String headerMiddle;
+
+    public Style(String headerLineSeparator, String lineSeparator, String columnSeparator, String lineColumnSeparator, boolean linesAfterEachRow) {
+      this.headerLineSeparator = headerLineSeparator;
+      this.lineSeparator = lineSeparator;
+      this.linesAfterEachRow = linesAfterEachRow;
+
+      this.columnLeft = columnSeparator + " ";
+      this.columnRight = " " + columnSeparator;
+      this.columnMiddle = " " + columnSeparator + " ";
+
+      this.lineLeft = "+" + lineSeparator;
+      this.lineRight = lineSeparator + "+";
+      this.lineMiddle = lineSeparator + "+" + lineSeparator;
+
+      this.headerLeft = "+" + headerLineSeparator;
+      this.headerRight = headerLineSeparator + "+";
+      this.headerMiddle = headerLineSeparator + "+" + headerLineSeparator;
+    }
+  }
+
+  public static final Style DEFAULT_STYLE = new Style("-", "-", "|", "+", false);
+  public static final Style RST_STYLE = new Style("=", "-", "|", "+", true);
+
+  /**
+   * Interface that this displayer will use to write out formatted text.
+   */
+  public interface TableDisplayerWriter {
+    /**
+     * Print out addition formatted text to the output
+     *
+     * @param text
+     */
+    void append(String text);
+
+    /**
+     * Flush and print new line
+     */
+    void newLineAndFlush();
+  }
+
+  public TableDisplayer(TableDisplayerWriter writer, Style style) {
+    setWriter(writer);
+    this.style = style;
+  }
+
+  /**
+   * Writer instance that we should use to write something out
+   */
+  private TableDisplayerWriter writer;
+
+  /**
+   * Style that should be used to the generated tables
+   */
+  private Style style;
+
+  /**
+   * Reset the writer if needed.
+   *
+   * @param writer
+   */
+  public void setWriter(TableDisplayerWriter writer) {
+    this.writer = writer;
+  }
+
   /**
    * Display given columns in nice table structure to given IO object.
    *
    * @param headers List of headers
    * @param columns Array of columns
    */
-  public static void display(List<String> headers, List<String> ...columns) {
+  public void display(List<String> headers, List<String> ...columns) {
-    assert headers != null;
     assert columns != null;
-    assert headers.size() == columns.length;
+    assert columns.length >= 1;
+    assert writer != null;
+    if(headers != null) {
+      assert headers.size() == columns.length;
+    }
 
     // Count of columns
-    int columnCount = headers.size();
+    int columnCount = columns.length;
 
     // List of all maximal widths of each column
     List<Integer> widths = new LinkedList<Integer>();
     for(int i = 0; i < columnCount; i++) {
-      widths.add(getMaximalWidth(headers.get(i), columns[i]));
+      widths.add(getMaximalWidth(headers != null ? headers.get(i) : null, columns[i]));
     }
 
     // First line is border
     drawLine(widths);
 
-    // Print out header (text is centralised)
+    if(headers != null) {
-    print("| ");
+      // Print out header (text is centralised)
-    for(int i = 0 ; i < columnCount; i++) {
+      print(style.columnLeft);
-      print(StringUtils.center(headers.get(i), widths.get(i), ' '));
+      for (int i = 0; i < columnCount; i++) {
-      print((i == columnCount -1) ? " |" : " | ");
+        print(StringUtils.center(headers.get(i), widths.get(i), ' '));
-    }
+        print((i == columnCount - 1) ? style.columnRight : style.columnMiddle);
-    println();
+      }
+      println();
 
-    // End up header by border
+      // End up header by border
-    drawLine(widths);
+      drawHeaderLine(widths);
+    }
 
     // Number of rows in the table
     int rows = getMaximalRows(columns);
 
     // Print out each row
     for(int row = 0 ; row < rows; row++) {
-      print("| ");
+      print(style.columnLeft);
       for(int i = 0 ; i < columnCount; i++) {
         print(StringUtils.rightPad(columns[i].get(row), widths.get(i), ' '));
-        print((i == columnCount -1) ? " |" : " | ");
+        print((i == columnCount - 1) ? style.columnRight : style.columnMiddle);
+
       }
       println();
+
+      if(style.linesAfterEachRow) {
+        drawLine(widths);
+      }
     }
 
     // End table by final border
-    drawLine(widths);
+    if(!style.linesAfterEachRow) {
+      drawLine(widths);
+    }
   }
 
   /**
@@ -85,12 +177,19 @@ public static void display(List<String> headers, List<String> ...columns) {
    *
    * @param widths List of widths of each column
    */
-  private static void drawLine(List<Integer> widths) {
+  private void drawLine(List<Integer> widths) {
+    drawLine(widths, style.lineLeft, style.lineRight, style.lineMiddle, style.lineSeparator);
+  }
+  private void drawHeaderLine(List<Integer> widths) {
+    drawLine(widths, style.headerLeft, style.headerRight, style.headerMiddle, style.headerLineSeparator);
+  }
+
+  private void drawLine(List<Integer> widths, String left, String right, String middle, String line) {
     int last = widths.size() - 1;
-    print("+-");
+    print(left);
     for(int i = 0; i < widths.size(); i++) {
-      print(StringUtils.repeat("-", widths.get(i)));
+      print(StringUtils.repeat(line, widths.get(i)));
-      print((i == last) ? "-+" : "-+-");
+      print((i == last) ? right : middle);
     }
     println();
   }
@@ -102,11 +201,10 @@ private static void drawLine(List<Integer> widths) {
    * @param column All column values
    * @return Maximal
    */
-  private static int getMaximalWidth(String header, List<String> column) {
+  private int getMaximalWidth(String header, List<String> column) {
-    assert header != null;
     assert column != null;
 
-    int max = header.length();
+    int max = header != null ? header.length() : 0;
 
     for(String value : column) {
       if(value != null && value.length() > max) {
@@ -123,7 +221,7 @@ private static int getMaximalWidth(String header, List<String> column) {
    * @param columns Array with all column values
    * @return
    */
-  private static int getMaximalRows(List<String>... columns) {
+  private int getMaximalRows(List<String>... columns) {
     int max = 0;
 
     for(List<String> column : columns) {
@@ -135,7 +233,12 @@ private static int getMaximalRows(List<String>... columns) {
     return max;
   }
 
-  private TableDisplayer() {
+  private void print(String text) {
-    // Instantiation is prohibited
+    writer.append(text);
   }
+
+  private void println() {
+    writer.newLineAndFlush();
+  }
+
 }