ItemSetWriter.java

package org.activityinfo.server.endpoint.odk;

import com.google.common.base.Charsets;

import java.io.*;

public class ItemSetWriter {
    private final Writer writer;

    // These are defined in
    // https://code.google.com/p/opendatakit/source/browse/src/org/odk/collect/android/external/ExternalSQLiteOpenHelper.java?repo=collect

    private static final char DELIMITING_CHAR = ',';
    private static final char QUOTE_CHAR = '"';
    private static final char ESCAPE_CHAR = '\0';

    ItemSetWriter(OutputStream out) throws IOException {
        this.writer = new OutputStreamWriter(out, Charsets.UTF_8);
        append("list_name,name,label\n");
    }

    public void writeItem(String listName, String name, String label) throws IOException {
        append(listName);
        appendDelimiter();
        append(name);
        appendDelimiter();
        appendEscaped(label);
        appendNewline();
    }

    private void appendEscaped(String label) throws IOException {
        writer.append(QUOTE_CHAR);
        for(int i=0;i!=label.length();++i) {
            char c = label.charAt(i);
            if(c == '\n' || c == '\r') {
                writer.append(' ');
            } else {
                if (c == QUOTE_CHAR) {
                    writer.append(ESCAPE_CHAR);
                }
                writer.append(c);
            }
        }
        writer.append(QUOTE_CHAR);
    }

    private Writer appendDelimiter() throws IOException {
        return writer.append(',');
    }

    private Writer append(String listName) throws IOException {
        return writer.append(listName);
    }

    private Writer appendNewline() throws IOException {
        return writer.append('\n');
    }

    public void flush() throws IOException {
        writer.flush();
    }

}