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)); *{ rorir
} P{o)Ir8Tt
for(int i=0;i<nEndPos.length-1;i++) kq}byv}3I
{ jYp!?%!
nEndPos = nStartPos[i+1]; D4L&6[W
} g{'f%bkG
nEndPos[nEndPos.length-1] = nFileLength; aw*]b.f
} Z*k(Q5&U
} JN wI{
ng%[yY
eh9?GUr5
//启动子线程 G[k3`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H,(vTthd
for(int i=0;i<nStartPos.length;i++) ~F,~^r!Jtu
{ w ,j*I7V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |3]/CrR_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `DYhGk
nStartPos,nEndPos,i); GAj%o]}u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gzs\C{4D
fileSplitterFetch.start(); wMVUTm
} %/A>'p,~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cfIC(d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5 bI:xL}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5MnP6(3$
nEndPos = " + nFileLength); l2Sar1~1
// fileSplitterFetch[nPos.length-1].start(); vD#U+
(=!At)O
{[!<yUJ`S#
//等待子线程结束 ,`HweIq(
//int count = 0; R #wZW&N
//是否结束while循环 ,j_js8r
boolean breakWhile = false; lx|Aw@C3~
R%jOgZG
z x-[@G
while(!bStop) j}uL
{ I-R7+o
write_nPos(); -qP)L;n
Utility.sleep(500); <e UsMo<
breakWhile = true; MH.+pqIv^
JR]2Ray
aF 2vgE\
for(int i=0;i<nStartPos.length;i++) lx+;<la
{ H,%bKl#
if(!fileSplitterFetch.bDownOver) ;oOTL'Vu
{ Ph=NH8
breakWhile = false; l2LQV]l
break; E+/Nicn=
} tc'iKJ5)
} :H&Q!\a
if(breakWhile) h?xgOb!4
break; p7|I>8ur.
d'';0[W)
}k }=e
//count++; nYx /q
//if(count>4) @\g}I`_M
// siteStop(); x {NBhq(4
} GJ%^hr`P
0Q{lyu
}h^ fX
System.err.println("文件下载结束！"); nq!=9r
} IH`Q=Pj
catch(Exception e){e.printStackTrace ();} FDl/7P`b(
} C'I&<
sx#O3*'>1
76w[X=Fv
//获得文件长度 5sJ>+Rg
public long getFileSize() )h]+cGM
{ 7z;2J;u`n
int nFileLength = -1; <W0(!<U
try{ ??/bI~Sd
URL url = new URL(siteInfoBean.getSSiteURL()); zx$YNjeV
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b\"F6TF:
httpConnection.setRequestProperty("User-Agent","NetFox"); 6:2*<
"pO
{?yVA
int responseCode=httpConnection.getResponseCode(); ^Gd1T
if(responseCode>=400) d_,Mylk
{ D|zuj]
processErrorCode(responseCode); {"'M2w:|D1
return -2; //-2 represent access is error 4np2I~ !
} ) f~;P+
|.c4y*
%NkiYiA
String sHeader; fS"u"]j*e
nuq@m0t\#
I2/am8!u%
for(int i=1;;i++) $[X][[
{ I7U/={[J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3P0z$jh"H
//Utility.log(in.readLine()); \aJ>?
sHeader=httpConnection.getHeaderFieldKey(i); Osqk#Oh
if(sHeader!=null) 5,;\zSz
{ v\w*VCjoV
if(sHeader.equals("Content-Length")) zLl-{Kk
{ T9c7cp[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bhUE!h<
break; r%;|gIky
} 8U@f/P
} Vs"b
else gOg7:VPG
break; +k6` tl~*
} mPA)G,^
} $'\kK,=
catch(IOException e){e.printStackTrace ();} 5 SQ!^1R 9
catch(Exception e){e.printStackTrace ();} uRy}HLZ"
|}d^lQ9
j*QdD\)
Utility.log(nFileLength); @|(cr: (=H
w yxPvI`
`RY}g;
return nFileLength; q#j[0,^ $
} -9LvAV>
q!W,2xqZoq
>4ex5
//保存下载信息（文件指针位置） ?J$k 5;
private void write_nPos() YAXd
{ mZU L}[xf
try{ d\qszYP[
output = new DataOutputStream(new FileOutputStream(tmpFile)); -|'@:cIZ
output.writeInt(nStartPos.length); ir'<H<t2
for(int i=0;i<nStartPos.length;i++) PZ/tkw
{ HxK'u4I
// output.writeLong(nPos); l8E))oz1T
output.writeLong(fileSplitterFetch.nStartPos); X#T|.mCdC
output.writeLong(fileSplitterFetch.nEndPos); dkg`T#}
} OR&pGoW
output.close(); 4(,.<#
} ?n<F?~
catch(IOException e){e.printStackTrace ();} 1[OY-G
catch(Exception e){e.printStackTrace ();} UZ/LR
} +m JG:n
SkV pZh
i$pUUK
//读取保存的下载信息（文件指针位置） ]+G\1SN~
private void read_nPos() F$>#P7ph\a
{ @mw1__?
try{ J4]"@0?6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |j"C52Q
int nCount = input.readInt(); 7r,GdP.
nStartPos = new long[nCount]; HpbwW=;V
nEndPos = new long[nCount]; ],AtR1k
for(int i=0;i<nStartPos.length;i++) idBdaZg
{ G>^= Bm_$
nStartPos = input.readLong(); s]yZ<uA
nEndPos = input.readLong(); 5[\g87\
} %^W(sB$b
input.close(); Nj4r[5K
} bZSt<cH3
catch(IOException e){e.printStackTrace ();} :M;|0w*b
catch(Exception e){e.printStackTrace ();} j*2/[Eq
} N]8/l:@
n<EIu
l
private void processErrorCode(int nErrorCode) %Lx#7bR U
{ gT[]"ZT7
System.err.println("Error Code : " + nErrorCode); &hVf=We
} s4 ,`
UptKN|S&V
W SvhC
//停止文件下载 c&#Q`m
public void siteStop() &%3}'&EBv
{ 11S{XbU
bStop = true; DM6(8df(
for(int i=0;i<nStartPos.length;i++) 0(5qVJ12
fileSplitterFetch.splitterStop(); o7tlkSZ
{2xc/
<F}j;mX
} =sAOWI,8!
} <qoc)p=__
//负责部分文件的抓取 3-y2i/4}$
**FileSplitterFetch.java {niV63$m
*/ 9-#=xE9'U
package NetFox; t`6~ud>
]q#"8=
=J-&usX
import java.io.*; UM1h[#?&V)
import java.net.*; Cs]\3R|D`
N#OO{`":Z`
A;xH{vo{
public class FileSplitterFetch extends Thread { |em_l$oGc
&4t=Y`]SL
}!kvoV)]1
String sURL; //File URL $*fEgU% c
long nStartPos; //File Snippet Start Position k:U%#rb;
long nEndPos; //File Snippet End Position Fyz1LOH[X
int nThreadID; //Thread's ID fsKZ
boolean bDownOver = false; //Downing is over 41C6ey
boolean bStop = false; //Stop identical +s+E!=s
FileAccessI fileAccessI = null; //File Access interface !9S!zRy@
,=u!hg
F{&0(6^p!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :2t?0YR
{ ;k1VY Ie}
this.sURL = sURL; R,hwn2@B
this.nStartPos = nStart; LqQ&4I
this.nEndPos = nEnd; /KgP<2p
nThreadID = id; gE&83i"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |@D%y&
} (Kkqyrb
w`Cs,
St3/mDtH
public void run() x50ZwV&j
{ ,7Q b24A
while(nStartPos < nEndPos && !bStop) Xj6?,J
{ T ^`R
TwZmZE ?!
F^DDN7AKH
try{ Q=498Y~x
URL url = new URL(sURL); U)S!@2(4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VPDd*32HC
httpConnection.setRequestProperty("User-Agent","NetFox"); V?Ca[
String sProperty = "bytes="+nStartPos+"-"; 2,6|l.WFpE
httpConnection.setRequestProperty("RANGE",sProperty); r[&/*~xL
Utility.log(sProperty); 4:s!mHcz
C/z0/mk
kSqMI'89
InputStream input = httpConnection.getInputStream(); =.q8*7UY
//logResponseHead(httpConnection); *edhJUT
\avgXndI
JN<u4\e{-&
byte[] b = new byte[1024]; N9AM% H$7
int nRead; Z2{G{]EV(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4q`e<!MP)q
{ =(as{,j
nStartPos += fileAccessI.write(b,0,nRead); U=KFbL1Q
//if(nThreadID == 1) -]Q6Ril
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ,uhOf! |
} }woNI
$mDlS
X2C&q$8
Utility.log("Thread " + nThreadID + " is over!"); Pu0O6@Rg
bDownOver = true; s#C~HK
//nPos = fileAccessI.write (b,0,nRead); Ov~>* [
} mRD'@n
catch(Exception e){e.printStackTrace ();} :LMLY<8>9
} `BKV/Xl
} GPU,.s"&(
$r/tVu2!W
.hytn`+9
//打印回应的头信息 ^yVKW5x
public void logResponseHead(HttpURLConnection con) &6#Ft]6~
{ fpPHw)dTd
for(int i=1;;i++) OOX[xv!b
{ #bdSH)V
String header=con.getHeaderFieldKey(i); UNKr FYl
if(header!=null) ~BD 80s:f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }SBpc{ch
Utility.log(header+" : "+con.getHeaderField(header)); GMYfcZ/,K
else x`gsD3C
break; ^Y+P(o$HM
} .l ufE
} j21nh>d
)i*-j=
{G4{4D }
public void splitterStop() -}Q^A_xK
{ ).9m6.%Uk
bStop = true; YgW 50)q^
} DmpG35Jk
`\5u/i'Ca!
X) xeq
} +{pS2I}d
`oGL==
kF29~
/* 7c aV-8:
**FileAccess.java tw%z!u[a
*//文件访问(定位，写) Dt\rMSjZ9
package NetFox; a\?-uJ+
import java.io.*; UbSAyf
3"y,UtKGa
i*ErxWzu
public class FileAccessI implements Serializable{ y ZR\(\?<
1/%g VB8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LyWgaf#/d
RandomAccessFile oSavedFile; )$7-CNWr~
long nPos; KBkS>0;X
.sR=Mf7T
\zGmZZ
public FileAccessI() throws IOException eY#_!{*Wn
{ @<,YUp,%S
this("",0); xY94v
} oVYW'~OID
=UMqa;\K
65||]l
public FileAccessI(String sName,long nPos) throws IOException 6A,-?W'\
{ 2E*h,Mo
oSavedFile = new RandomAccessFile(sName,"rw"); mel(C1b"j/
this.nPos = nPos; IFfB3{J
oSavedFile.seek(nPos); 4fa2_
} }10ZPaHjl+
;j^C35
(n0h#%
public synchronized int write(byte[] b,int nStart,int nLen) T5b*Ia
{ O[O[E}8#
int n = -1; /<-@8CC<
try{ 99tKs
oSavedFile.write(b,nStart,nLen); \1R<GBC4
n = nLen; %6eQ;Rp*
} t0-)\kXcA
catch(IOException e) uA~T.b\
{ C|hD^m
e.printStackTrace (); BA(PWX`H
} dD.;P=AP
{]V+C=`
hX&Jq%{oa
return n; gOL-b9W
} asd3J
6h%_\I.Z[[
3yp?|>e
} g886RhCe
LL"c 9jb4z
Kdr7JQYzuz
/* \PJpy^i
**SiteInfoBean.java Wd<|DmSy
*/ W34_@,GD
package NetFox; 3:~ *cU
5nSi29C
"-afHXED
public class SiteInfoBean { L$Yg*]\
~D1&CT#s
(`me}8
private String sSiteURL; //Site's URL [ 30ta<-
private String sFilePath; //Saved File's Path sm9/sX!
private String sFileName; //Saved File's Name |O4LR,{G.w
private int nSplitter; //Count of Splited Downloading File rS&"UH?c7
*iwVB^^$
Iq["(!7E5
public SiteInfoBean() =s5g9n+7
{//nSplitter的缺省值为5 H2 Gj(Nc-
//default value of nSplitter is 5 $3c9iVK~_
this("","","",5); )Lb?ZXT3
} N6UPD11}6
wpI_yp
![H{ndH!Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Wv7hY"
{ yi&6HNb
sSiteURL= sURL; 2.PZtl
sFilePath = sPath; K);)$8K
sFileName = sName; 5zi}OGtXv
this.nSplitter = nSpiltter; |zCT~#
x*7Q
"HwSW4a]
} $LOwuvu>
o>i@2_r\&H
6haw\ *
public String getSSiteURL() 7GG:1:2+>
{ ,d`6 {ll
return sSiteURL; T:!f_mu|
} nBkzNb{"AZ
~`c(7
tB{HH%cV
public void setSSiteURL(String value) YU,fx<c
{ Hzc5BC
sSiteURL = value; R8bKE(*rxj
} 1<;RI?R[9
T]UrKj/iF
,+GS.]8<
public String getSFilePath() j{&$_
{ f~t5[D(\Q,
return sFilePath; me ,lE-
} KEfwsNSc%
pG(Fw>
W87kE?,
public void setSFilePath(String value) 4H*M^?h\#
{ h-+vNhH
sFilePath = value; ?d' vIpzO!
} U+-R2w]#q_
7#+>1 "\
C'.^2s#e8
public String getSFileName() 'PWX19
{ y%!zXK`cl]
return sFileName; {!>'# F^e
} :`B70D8ku
^/ZNdwx
f)1*%zg%
public void setSFileName(String value) \__xTL\
{ Hj97&C{Q^
sFileName = value; 1A}#j
} zGaqYbQD
T6nc/|Ot
MWq1 "c
public int getNSplitter() ":!1gC
{ XImX1GH
return nSplitter; a^g}Z7D'T
} Z9q1z~qSQ
ac%x\e$
eZ8DW6l*
public void setNSplitter(int nCount) ^TEFKx}PX
{ szUJh9-
nSplitter = nCount; *-X`^R
} ;pt.)5
} hV}C.- 6h
zK>}x=
h@CP
/* IC:>60A,]
**Utility.java uNf97*~_
*/ e7r3o,!
package NetFox; 9c{T|+]
ov\+&=IRG
]ONBr(M\
public class Utility { N<~LgH
6%Pvh- ~_
Hq aay
public Utility() Ij2Th]
{ a"m-&mN
]jSRO30H3<
j~Mx^ivwj
} %m##i
$6]1T>
//线程睡眠 _0o65?F
public static void sleep(int nSecond) KM9H<;A
{ WDJ rN
try{ /BwG\GhM
Thread.sleep(nSecond); 1h3`y
} 0-:dzf
catch(Exception e) %^l&:\ hy
{ R>hL.+l.
e.printStackTrace (); k>F>y|m
} \3T[Cy|5|
} d>O/Zal
;sAe#b
//日志 rN'8,CV
public static void log(String sMsg) M>ntldV#g%
{ PkcvUJV
System.err.println(sMsg); 7U:{=+oLR
} v >cPr(
L),r\#Y(v
{__NVv
public static void log(int sMsg) }b^x#HC
{ vG:S(/\>
System.err.println(sMsg); V;"Rp-`^
} !b?cY{
} K!(hj '0.
U#`2~Qv/1
D*'sOB(
/* B\tm
**TestMethod.java 70{B/ ($
*/ lE$(*1H
package NetFox; [IgqK5@
wW7#M
e4FR)d0x
public class TestMethod { aH\A
ko"xR%Q
(5e4>p&+
public TestMethod() gF:|j(
{ ///xx/weblogic60b2_win.exe qq"0X! w
try{ =1\mLI}@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0|ekwTx.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f^lhdZ\
SiteFileFetch fileFetch = new SiteFileFetch(bean); q+ `QiPj
fileFetch.start(); qWS"I+o,S
} : . PRM+
catch(Exception e){e.printStackTrace ();} W4(GI]`_+
6Zx5^f(qd
dEkAUH
} #u3E{NB
HGF&'@dn
vXg^K}a#
public static void main(String[] args) _<'?s>(U'
{ T1%}H3
new TestMethod(); xT-`dS0u
} h)^|VM
} zU'7x U-
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