问如何用Java读取sas文件格式

EN

<dependency>
    <groupId>org.thshsh</groupId>
    <artifactId>sas-utils</artifactId>
    <version>1.0.0-SNAPSHOT</version>
</dependency>

package com.onepointltd.sas.xpt;

import org.thshsh.sas.Variable;
import org.thshsh.sas.VariableType;
import org.thshsh.sas.xpt.DatasetXpt;
import org.thshsh.sas.xpt.LibraryXpt;
import org.thshsh.sas.xpt.ParserXpt;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * Converts the data in an xpt file to JSON array.
 */
public class JsonConversion {

    private JsonConversion() {}

    public static Collection<String> convertToJson(String xptFileStr) throws IOException {
        File xptFile = new File(xptFileStr);
        if(!xptFile.exists()) {
            throw new FileNotFoundException(String.format("File %s does not exist", xptFileStr));
        }
        return convertToJson(xptFile);
    }

    public static Collection<String> convertToJson(File xptFile) throws IOException {
        LibraryXpt library = ParserXpt.parseLibrary(xptFile);
        List<DatasetXpt> datasets = library.getDatasets();
        if(datasets == null || datasets.isEmpty()) {
            return Collections.emptyList();
        }
        return datasets.stream().map(datasetXpt -> {
            try {
                return "[" + datasetXpt.streamObservations(xptFile).map(observation -> {
                    Map<Variable, Object> values = observation.getValues();
                    return "{" + values.entrySet().stream().map((entry) -> {
                        Variable key = entry.getKey();
                        Object value = entry.getValue();
                        VariableType type = key.getType();
                        if (type == VariableType.Character) {
                            value = value == null ? "" : quote(value.toString().trim());
                        }
                        String name = key.getName();
                        return String.format("%s: %s", quote(name), value);
                    }).collect(Collectors.joining(",")) + "}";
                }).collect(Collectors.joining(",")) + "]";
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }).collect(Collectors.toList());
    }

    public static String quote(String string) {
        if (string == null || string.length() == 0) {
            return "\"\"";
        }

        char         c = 0;
        int          i;
        int          len = string.length();
        StringBuilder sb = new StringBuilder(len + 4);
        String       t;

        sb.append('"');
        for (i = 0; i < len; i += 1) {
            c = string.charAt(i);
            switch (c) {
                case '\\':
                case '"':
                    sb.append('\\');
                    sb.append(c);
                    break;
                case '/':
                    //                if (b == '<') {
                    sb.append('\\');
                    //                }
                    sb.append(c);
                    break;
                case '\b':
                    sb.append("\\b");
                    break;
                case '\t':
                    sb.append("\\t");
                    break;
                case '\n':
                    sb.append("\\n");
                    break;
                case '\f':
                    sb.append("\\f");
                    break;
                case '\r':
                    sb.append("\\r");
                    break;
                default:
                    if (c < ' ') {
                        t = "000" + Integer.toHexString(c);
                        sb.append("\\u" + t.substring(t.length() - 4));
                    } else {
                        sb.append(c);
                    }
            }
        }
        sb.append('"');
        return sb.toString();
    }
}