http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); %(Nu"3|$K=
} ._~_OVU
for(int i=0;i<nEndPos.length-1;i++) (X,Ua+{
{ za1MSR
nEndPos = nStartPos[i+1]; *|Q'?ty(x
} e4ydn
nEndPos[nEndPos.length-1] = nFileLength; x$J1%K*
} 2+TCFpv
} *.ri8
X7?p$!M6;B
9loWh5_1Z
//启动子线程 U GQ{QH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {%9)l,
for(int i=0;i<nStartPos.length;i++) \ZigG{
{ S WVeUL#5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =2\k Jv3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nY'0*:'u
nStartPos,nEndPos,i); tjBs>w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rC14X}X6
fileSplitterFetch.start(); \$/)o1SG
} x:88E78
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7;#9\a:R?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {xW?v;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q$Ga.fI
nEndPos = " + nFileLength); JWr:/?
// fileSplitterFetch[nPos.length-1].start(); bA@!0,m
G6w&C^J*8>
f/~"_O%
//等待子线程结束 YxlV2hcX;
//int count = 0; EQSOEf[
//是否结束while循环 ,@tkL!"9q
boolean breakWhile = false; 5:Pp62
<h4"^9hL
$]%;u: Sa
while(!bStop) /WRS6n
{ 2BXpk^d5y
write_nPos(); r )ZUeHt}w
Utility.sleep(500); }Xr-xh\v
breakWhile = true; w0)V3
4[ M!x
{2vk<
for(int i=0;i<nStartPos.length;i++) lTvI;zy
{ 6b~Zv$5^Y-
if(!fileSplitterFetch.bDownOver) ]{{A/ j\
{ N#Y%+1
breakWhile = false; h=.|!u
break; nW3-)Q89
} yMq&9R9F
} UQ:H3
if(breakWhile) ;o8C(5xE|
break; NKvBNf|D
dFS>uIT7X
+(x^5~QX
//count++; O%H_._#N`
//if(count>4) l9lBhltOH
// siteStop(); MIo<sJuv
} x9Fga_
g34<0%6jd
K]Q#B|_T
System.err.println("文件下载结束！"); l~;H~h!h/
} 4*}[h9J}\
catch(Exception e){e.printStackTrace ();} l Q]&:%^\
} rmu5K$pl
p @&>{hi@
!Y>lAxd
//获得文件长度 S_/9eI~X
public long getFileSize() <`i"5`J
{ 15+>W4v
int nFileLength = -1; |!E>I
try{ -=iGl5P?
URL url = new URL(siteInfoBean.getSSiteURL()); "~(qp_AI
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z8_m<uewz
httpConnection.setRequestProperty("User-Agent","NetFox"); ns[v.YDL
{a\O7$A\F
5ppOG_
int responseCode=httpConnection.getResponseCode(); 'MRvH lCM
if(responseCode>=400) (9% ki$=}+
{ bXF>{%(}E
processErrorCode(responseCode); Oi AZA<
return -2; //-2 represent access is error -$**/~0zU
} @X4Ur+d
a yn6k=F
V>ML-s9
String sHeader; L^bt-QbhO
7K,Quq.%+
:K>v F`SM
for(int i=1;;i++) 3sIW4Cs7)U
{ MGze IrV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 59!yz'feF
//Utility.log(in.readLine()); t~ruP',~\
sHeader=httpConnection.getHeaderFieldKey(i); $}V<Um
if(sHeader!=null) zI$^yk-vn
{ &E0L7?l
if(sHeader.equals("Content-Length")) 6E/>]3~!
{ wwrP7T+d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dE19_KPm[j
break; "[2CV!_
} l*>t@:2J
} 'KB\K)cD=3
else 6w(Mb~[n
break; +KgoLa
} ZUP\)[~
} M #'br<]
catch(IOException e){e.printStackTrace ();} '?=SnjMX
catch(Exception e){e.printStackTrace ();} L9Sd4L_e
QEKSbxL\W
&IsQgS7R
Utility.log(nFileLength); RO[Ko-m|/N
Ls{z5*<FM
qX{"R.d
return nFileLength; %E#OUo[y/
} VN[C%C
,Tc3koi
Lh3>xZy"-z
//保存下载信息（文件指针位置） `Fa49B|`D
private void write_nPos() x2x)y08
{ cKuU#&FaV
try{ ?T=]?[
output = new DataOutputStream(new FileOutputStream(tmpFile)); !+T\}1f7d
output.writeInt(nStartPos.length); OLh`R]Sd
for(int i=0;i<nStartPos.length;i++) x{{QS$6v
{ !$Aijd s5
// output.writeLong(nPos); ]T|9>o!
output.writeLong(fileSplitterFetch.nStartPos); Ot}fGiio
output.writeLong(fileSplitterFetch.nEndPos); )OQhtxK
} WeDeD\zy
output.close(); h07Z.q ;
} L1=3_fO
catch(IOException e){e.printStackTrace ();} K*iy^}
catch(Exception e){e.printStackTrace ();} ,<?iL~> %
} d\aKGq;8C
Q|QVm,m
?#; oqH<
//读取保存的下载信息（文件指针位置） = ms(dr^n
private void read_nPos() Rs_0xh
{ f?8cO#GU
try{ Ww5c9orXn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6BM[RL?T
int nCount = input.readInt(); [ []'U'
nStartPos = new long[nCount]; 0^'A^
nEndPos = new long[nCount]; MV +R$
for(int i=0;i<nStartPos.length;i++) ^kZfE"iE2
{ "<o[X ?u
nStartPos = input.readLong(); M S 3?#b
nEndPos = input.readLong(); xg=}MoX
} 2VmQ%y6e"
input.close(); - s[=$pDU
} piYv}4;:(
catch(IOException e){e.printStackTrace ();} vSty.:bY\p
catch(Exception e){e.printStackTrace ();} X"WKgC g$
} T=r-6eN
/2}o:vLj
1HQh%dZZ
private void processErrorCode(int nErrorCode) ?#8',:
{ O@JgVdgf
System.err.println("Error Code : " + nErrorCode); Y g>W.wA
} gXr"],OM;
@3`:aWda
~RcI+jR)
//停止文件下载 5/x"!Jk
public void siteStop() b3(pRg[Fp
{ BiGB<Jr
bStop = true; Q'-V\G)11
for(int i=0;i<nStartPos.length;i++) VBc[(8o
fileSplitterFetch.splitterStop(); eduaG,+k7p
O7@CAr
Eu/~4:XN
} u I$|M
} \zj _6Os
//负责部分文件的抓取 s_]p6M
**FileSplitterFetch.java /H#- \r&r
*/ 2|'v[
package NetFox; WrK!]17or
rZRcy9$y>
NGYliP,.6
import java.io.*; 5dffFe
import java.net.*; ]zp5 6U|xa
u\YH,
V|=PaO
public class FileSplitterFetch extends Thread { _XT],"
'[#a-8-JY_
tX;00g;U.
String sURL; //File URL 4d&#NP
long nStartPos; //File Snippet Start Position o(xRq;i
long nEndPos; //File Snippet End Position #_yQv?J
int nThreadID; //Thread's ID rfqw/o
boolean bDownOver = false; //Downing is over Gvo(iOU
boolean bStop = false; //Stop identical @$FE}j_
FileAccessI fileAccessI = null; //File Access interface |1^>n,C
3wXmX
>Gbj1>C}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException EtN@ 6xP
{ bc}X.IC
this.sURL = sURL; 5,=Yi$x
this.nStartPos = nStart; TR!^wB<F
this.nEndPos = nEnd; 1);$#Dlt k
nThreadID = id; RZ)sCR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B5J!&suX
} mhnjYK9
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8@%Xd^
public void run() [% chN/
{ [c4.E"
while(nStartPos < nEndPos && !bStop) ;9r Z{'i+|
{ QX(x6y>Q
:T~Aa(%(
/UeLf$%ZW
try{ `x:znp}'
URL url = new URL(sURL); qh Ezv~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A^7!:^%K
httpConnection.setRequestProperty("User-Agent","NetFox"); YArNJ5z=
String sProperty = "bytes="+nStartPos+"-"; 1|Y(XB^os(
httpConnection.setRequestProperty("RANGE",sProperty); w+VeT@
Utility.log(sProperty); 8+vZ9!7
?]gZg[
@C)O[&Sk
InputStream input = httpConnection.getInputStream(); lhg3 }dW
//logResponseHead(httpConnection); Li ,B,
E_&Hje|J_[
1lyJ;6i6L
byte[] b = new byte[1024]; ^q6H =Dl
int nRead; b ABx'E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fs4pAB#F
{ Hh @q;0ni
nStartPos += fileAccessI.write(b,0,nRead); Mr'}IX5
//if(nThreadID == 1) M,V+bt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BqZ^I eC$
} #QJ mAA
Z:f0>
Z&8 7Aj
Utility.log("Thread " + nThreadID + " is over!"); Vzy]N6QT{
bDownOver = true; ?7-#iC`
//nPos = fileAccessI.write (b,0,nRead); 7}bjJR "
} ];Whvdnv
catch(Exception e){e.printStackTrace ();} lJ]r%YlF
} !f_GR Pj'
} P# 2&?.d\
zi:F/TlUC
bb;fV
//打印回应的头信息 mY-Z$8r
public void logResponseHead(HttpURLConnection con) KtJE
{ ZWMX!>o<
for(int i=1;;i++) WrbDB-uM
{ J#Fe"
String header=con.getHeaderFieldKey(i); 8o8FL~&]
if(header!=null) m^zx&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m}.ru)^p
Utility.log(header+" : "+con.getHeaderField(header)); Hxr2Q]c?u
else WO*yJ`9]
break; I Vy,A7f
} Bc}<B:q%b
} `7jm
7'FDI`e[
X:-X3mV9{
public void splitterStop() :NU-C!eT
{ vy/U""w`
bStop = true; RBx`<iBe
} TI}H(XL(
.Pq8C
qx 3.oU
} k/l@P
4,9AoK)yp
=f@O~nGm
/* tYIHsm\b
**FileAccess.java #%VprcEK
*//文件访问(定位，写) TUhp
package NetFox; (Br$(XJoK}
import java.io.*; `.;7O27A^%
cb&y8!ci~
uuj"Er31
public class FileAccessI implements Serializable{ gT @YG;
IcL3.(!]l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d;S:<]l'
RandomAccessFile oSavedFile; ->wY|7
long nPos; ;]fpdu{
hgj#VY$B
j>&n5?
public FileAccessI() throws IOException 567ot|cc
{ 5!#"8|oY
this("",0); el!Bi>b9c!
} w|WZEu:0|
^a; V-US
V$ 38
public FileAccessI(String sName,long nPos) throws IOException /iif@5lw{
{ +Smv<^bW
oSavedFile = new RandomAccessFile(sName,"rw"); |}Mkn4
this.nPos = nPos; sxL;o>{
oSavedFile.seek(nPos); ]wne2WXE
} mXc/sh")X
N=D Ynz_~
4:r^6m%%
public synchronized int write(byte[] b,int nStart,int nLen) QXJD'c
{ ZC"6B(d
int n = -1; |L;'In
try{ R $'}Z
oSavedFile.write(b,nStart,nLen); 3FPy"[[
n = nLen; &Wd,l$P<O
} 2?t(%uf]
catch(IOException e) NJqALm!(
{ (m;P,*
e.printStackTrace (); !qrF=a
} 4NR,"l)
miS+MK"
{J})f>x<xM
return n; %>I!mD"X\
} !P@u4FCs
QX%m4K/a
<eN>X:_N
} TG?;o/
?P`wLS^;
5[l3]HOO
/* 1+eC'&@Xjt
**SiteInfoBean.java -D:J$d 6R<
*/ W}L=JJo},
package NetFox; eE7Rd>
jLr8?Hyf
4L!{U@'
public class SiteInfoBean { IUd>jHp`6
ItM?nyA
c09]Cp<
private String sSiteURL; //Site's URL {w!}:8p
private String sFilePath; //Saved File's Path b@YSrjJ
private String sFileName; //Saved File's Name @1n0<V/
private int nSplitter; //Count of Splited Downloading File VPN@q<BV
7/Lbs
czMLvPXRx
public SiteInfoBean() bSz6O/A/
{//nSplitter的缺省值为5 LV8,nTYvE
//default value of nSplitter is 5 d,<ctd
this("","","",5); 9q* sR1
} Br#]FB|tD
] {NY;|&I'
,6t0w|@-k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) aF'Ik XG d
{ g?=B{V
sSiteURL= sURL; }d.R=A9L
sFilePath = sPath; $,i:#KT`
sFileName = sName; K:'pK1zy
this.nSplitter = nSpiltter; FC]? T
A1Q]KS@
2#+@bk>^{
} xmiF!R
R63"j\0
Y}1|/6eJ
public String getSSiteURL() &OI=rvDmo
{ .\U+`>4av
return sSiteURL; ZLL0 6p
} Nq*\{rb
0w+hf3K+:
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public void setSSiteURL(String value) L7D'wf
{ g"T~)SQP
sSiteURL = value; 2YwV}
} 5j]}/Aq
{xM%3
~]"}s(J;
public String getSFilePath() Q;5\( 0w5
{ $oxPmELtpe
return sFilePath; W:5m8aE\
} vO0ql
R1P,0Yf
WO)K*c1F
public void setSFilePath(String value) gVG :z_6
{ "r"Y9KODm
sFilePath = value; ^kt"n(P5
} v11mu2
H[>_LYZ8
}Bc6:a
public String getSFileName() -CL7^
{ '|FM|0~-J
return sFileName; c7iu[vE'+
} J=\Y4- "
E0)v;yRcw
ie$=3nZJ}
public void setSFileName(String value) ~!:F'}bj
{ m2_&rjGz
sFileName = value; ^1Yx'ua'
} JWn9&WK
;Rnb^t6Z
'|]zBpz
public int getNSplitter() |fw+{f
{ {Or|] 0
return nSplitter; ,/d-o;W
} Z&.FJZUP
Zb9@U: \
}(hE{((o
public void setNSplitter(int nCount) MnX2sX|
{ z4f5@
nSplitter = nCount; Y^6=_^
} t: [[5];E
} XD|&{/O
DG:=E/@
:\bttPw5
/* VWMCbg>R
**Utility.java LZoth+:
*/ x%(!+
package NetFox; hVGakp9WE
ho(Y?'^t3
_OrE{
public class Utility { Y/$SriC_+'
-Z;:_"&9
Jhj]rsGk
public Utility() H/L3w|2+
{ Z2$-},i
[j![R
<v2R6cj5
} \\/X+4|o'
-_314j=`/
//线程睡眠 [0~qs|27
public static void sleep(int nSecond) >K &b,o,[
{ '.dW>7
try{ t 1&p> v
Thread.sleep(nSecond); ar^`r!ABEh
} $K,aLcu
catch(Exception e) f a\cLC
{ lhjPS!A~
e.printStackTrace (); |QzPY8B9O
} nB:Bw8U"Q
} de`6%%|
mWGT (`|~/
//日志 Awr]@%I
public static void log(String sMsg) 5S7Z]DXiT8
{ Hv`Zc*
System.err.println(sMsg); M0"feq
} lO) B/N&
m#SZI}
~]yqJYiid^
public static void log(int sMsg) my} P\r.
{ L`Ic0}|lzy
System.err.println(sMsg); 3{_+dE"9
} G6J3F
} ILVbbC`D
.6'T;SoK>
J`V6zGgW
/* 1U9iNki
**TestMethod.java UG!&n@R
*/ Mr1pRIYMd
package NetFox; :5Vu.\,1
s e1ipn_A
xj~6,;83xR
public class TestMethod { WkO .
I3L1|!
x[?_F
public TestMethod() stDn{x.
{ ///xx/weblogic60b2_win.exe ::5-UxGL<2
try{ P#0_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FE5R ^W#u-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y%GV9
SiteFileFetch fileFetch = new SiteFileFetch(bean); D{4 Y:O&J
fileFetch.start(); e-s@@k
} Vnl~AQfk|
catch(Exception e){e.printStackTrace ();} #2MwmIeA
O7K))w
vd;wQ
} IR>Kka(B
"E8!{
LNg1q1P3
public static void main(String[] args) K)14v;@
{ <AIsNqr
new TestMethod(); F0!r9U((
} NMDNls&)k
} O]Hg4">f
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