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)); F3H:I"4
} _oMs `"4K
for(int i=0;i<nEndPos.length-1;i++) 5JXzfc9rL
{ 7(nz<z p
nEndPos = nStartPos[i+1]; <:kTTye|
} ]$XBd{\D{
nEndPos[nEndPos.length-1] = nFileLength; cNuuzA
} 'Wx\"]:
} (e bBH
Os]!B2j14
9;xL!cy
//启动子线程 w<I5@)i|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *`QdkVER
for(int i=0;i<nStartPos.length;i++) ~L4*b*W
{ zBrWm_R5T
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fw_bY/WN{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), / %U~lr
nStartPos,nEndPos,i); 3^iQe"P%a@
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2yCd:wg
fileSplitterFetch.start(); *x#&[>
} N('S2yfDR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )N%1%bg^-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FS]+s>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", MK!]y8+Z
nEndPos = " + nFileLength); hK9t}NE.O
// fileSplitterFetch[nPos.length-1].start(); J?qcRg`1E
5@r_<J<>
]C!Y~
//等待子线程结束 8g2-8pa{
//int count = 0; *Wuctu^9
//是否结束while循环 ]y)R C-N
boolean breakWhile = false; ]<o.aMdV
(x@i,Ba@
^V0{Ew/x
while(!bStop) c5mhl;+'
{ M~g~LhsF
write_nPos(); dWq/)%@t
Utility.sleep(500); q!9v}R3(
breakWhile = true; v|,[5IY
3 DO$^JJ.
1>*UbV<R;u
for(int i=0;i<nStartPos.length;i++) 0[$Mo3c+'
{ rz%[o,s
if(!fileSplitterFetch.bDownOver) 0D]Yz`n3
{ '#An+;x{
breakWhile = false; ;&t1FH#=
break; #G4~]Qml
} -XDP-Trk
} u`H@Q&(^wa
if(breakWhile) bTy'5"
break; 3Mh,NQB
T0]%(F/8
D=I5[t0c4
//count++; gQ@Pw4bA
//if(count>4) 65`'Upu
// siteStop(); A86lyBDQ*
} ZjI/zqBm
f)s_e
V~uA(3\U
System.err.println("文件下载结束！"); e2=,n6N]c
} -R8!"~o
catch(Exception e){e.printStackTrace ();} =ZJ?xA8
} wor'=byh\
>!v,`O1
g#KToOP
//获得文件长度 MIXrLh3
public long getFileSize() @,>=X:7
{ ~|B!.+
int nFileLength = -1; S1^Mw;?P
try{ X%R^)zKV
URL url = new URL(siteInfoBean.getSSiteURL()); NE>JtTF<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {'K;aJ'\
httpConnection.setRequestProperty("User-Agent","NetFox"); =R24h
w2C!>fJ]1
_%p9B#X<>
int responseCode=httpConnection.getResponseCode(); /CQQ^/
if(responseCode>=400) @2Y]p.$q
{ ZX5A%`<M
processErrorCode(responseCode); Z :i"|;
return -2; //-2 represent access is error .Zo9^0`C
} ~C*6V{Tj
4Uy>#IL
$j4?'-i=e
String sHeader; Kg0\Pvg8?T
CO)b'V,
]v,y(yl
for(int i=1;;i++) ]!Aze^7;
{ 6x3Ew2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OD@A+"
//Utility.log(in.readLine()); O@(.ei*HJ!
sHeader=httpConnection.getHeaderFieldKey(i); }${ZI
if(sHeader!=null) &=yqWW?
{ eiSO7cGy
if(sHeader.equals("Content-Length")) fdEj#Ux<H
{ %?G.lej,x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K|J#/
break; @j8L{FGnN
} YU\t+/b
} +7vh__
else }lvP|6Y: y
break; @_(@s*4W
} Ko1?jPE
} T+{'W
catch(IOException e){e.printStackTrace ();} #?d>S;)+
catch(Exception e){e.printStackTrace ();} Ywb)h^{!
kC#B7*[RM
Ex&RR< 5
Utility.log(nFileLength); (i~%4w=
9NoPrR=x1
eMd1%/[
return nFileLength; ~~E=E;9
} b({b5z.A
JI; i1@|b
6!=9V0G~
//保存下载信息（文件指针位置） |0pBBDw
private void write_nPos() UY& W]
{ xupdjT%4
try{ ?[fl$EG
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z5^UF2`Q
output.writeInt(nStartPos.length); |2]WA'q
for(int i=0;i<nStartPos.length;i++) WaK{/6?T,
{ }Mlz\'{
// output.writeLong(nPos); 7Qztc?XK
output.writeLong(fileSplitterFetch.nStartPos); LZbHK.G=
output.writeLong(fileSplitterFetch.nEndPos); "'dC>7*<
} >t<R6f_Q0
output.close(); ]CJ>iS!V
} aj-uk(r
catch(IOException e){e.printStackTrace ();} v+2qR0,LM
catch(Exception e){e.printStackTrace ();} Oes+na'^
} "@|V.d@
k <Sa<
2&f=4b`Z
//读取保存的下载信息（文件指针位置） WW/m /+
private void read_nPos() 2/gj@>dt
{ ~SUl,Cs
try{ ^?0,G>I%-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F(n))`(
int nCount = input.readInt(); 2x J5
nStartPos = new long[nCount]; >\Pj(,'
nEndPos = new long[nCount]; ]6 7wk
for(int i=0;i<nStartPos.length;i++) |,~A9
{ !7kOw65+0
nStartPos = input.readLong(); *)SgdC/f
nEndPos = input.readLong(); n>+W]I&E
} `\uv+^x{
input.close(); pKlT.<X7
} S|h m
catch(IOException e){e.printStackTrace ();} z4UQ:z@
catch(Exception e){e.printStackTrace ();} `^h##WaXap
} @G{DOxE*
Re ur#K
bL[W.O0
private void processErrorCode(int nErrorCode) W8rn8Rh
{ .`=PE&xq
System.err.println("Error Code : " + nErrorCode); } R6h
} j_<n~ri-
;lt;]7
%),O9*[9
//停止文件下载 pjn%CR`;
public void siteStop() nvs7s0@Fqe
{ cO+`8`kv
bStop = true; 74OM tLL$
for(int i=0;i<nStartPos.length;i++) |hyr(7
fileSplitterFetch.splitterStop(); ^>28>!"1
DKCy h`
h--!pE+
} ?wY.B
} gJv^v`X
//负责部分文件的抓取 {vlh,0~
**FileSplitterFetch.java a'~y'6
*/ / /rWc,c
package NetFox; Om~C0
~PAn _]Z
MUl+Oy>
import java.io.*; b=l}|)a
import java.net.*; ]TOY_K8"z#
VX%\_@
jX,~iZ_B
public class FileSplitterFetch extends Thread { g>oLc6T
=h!m/f^x
>D aS*r
String sURL; //File URL Vs{sB*:
long nStartPos; //File Snippet Start Position /q]@|5I
long nEndPos; //File Snippet End Position M 4?3l
int nThreadID; //Thread's ID 9hzU@m
boolean bDownOver = false; //Downing is over (*gpa:Sc
boolean bStop = false; //Stop identical &6EfybAt^_
FileAccessI fileAccessI = null; //File Access interface Br??Gdd
Pl6=._
]x\wP7x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ymvd=F
{ 1OL~)X3
this.sURL = sURL; VG^-aR_F
this.nStartPos = nStart; S22;g
this.nEndPos = nEnd; uIwyan-
nThreadID = id; i9"1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y_#wR/E)u{
} =ByW`
(*]Y<ve
hn.fX:}
public void run() mqw.v$>
{ t|lv6-Hy9
while(nStartPos < nEndPos && !bStop) 5. i;IOx
{ ^j7pF.j
{BU,kjv1g
F6/bq/s
try{ z{x -Vfd
URL url = new URL(sURL); EK^2 2vi$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NKrk*I"G
httpConnection.setRequestProperty("User-Agent","NetFox"); &aOOG8l
String sProperty = "bytes="+nStartPos+"-"; Y$^QH.h
httpConnection.setRequestProperty("RANGE",sProperty); Sm5"Q
Utility.log(sProperty); \266N;JrN
#>'0C6Xn
j!dklQh0
InputStream input = httpConnection.getInputStream(); \ZH=$c*W
//logResponseHead(httpConnection); ,sK-gw
7Cjrh"al"
J)]W[Nk
byte[] b = new byte[1024]; @<L.#gtP
int nRead; ?K"]XXsI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tA.C"
{ R,lr&;a8
nStartPos += fileAccessI.write(b,0,nRead); ^D)C|T
//if(nThreadID == 1) %94"e7Hy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #oI`j q
} '%N p9Iqt
N1rrKyL!$
%LyB~X
Utility.log("Thread " + nThreadID + " is over!"); V ALYA=w/
bDownOver = true; _QY "#
//nPos = fileAccessI.write (b,0,nRead); lki(_@3
} 8:MYeE5
catch(Exception e){e.printStackTrace ();} Q@R8qc=*
} "+AD+D
} J2rH<Fd[up
c9@*
kQ+5pFo3
//打印回应的头信息 HZNX1aQ|Q#
public void logResponseHead(HttpURLConnection con) v:'y&yS
{ 2+HiaYDZ
for(int i=1;;i++) $[Ns#7K
{ X+iULr.^`~
String header=con.getHeaderFieldKey(i); t<tBOesQ
if(header!=null) k?,g:[4!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Bb)J8,LQ
Utility.log(header+" : "+con.getHeaderField(header)); n)yqb
else )XFMlSx)
break; <Bwu N,}
} +7w>ujeeJA
} xS'So7:h
=0S7tNut
\c)XN<HH
public void splitterStop() {#MViBhd%
{ xUYSD
bStop = true; 0#G"{M
} )%6v~,'3Y
|j;`;"+B
6tM{cK%v1
} 2B#\683
%o-*~GQ@B
8eNGPuoL)
/* 7^1ikmYY
**FileAccess.java [0$Y@ek[
*//文件访问(定位，写) B(~D*H2T[
package NetFox; !u"Hf7/
import java.io.*; 1D$k:|pP~
rqIt}(J
"F^EfpcJ{9
public class FileAccessI implements Serializable{ .s+e hZ
KvgZx(.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Aq-v3$XL
RandomAccessFile oSavedFile; DE[y&]/C{
long nPos; pP .
-M4#dHR_!
E?-K_p
public FileAccessI() throws IOException l!1bmg#]$
{ UCQL~
this("",0); ,AJd2ix
} aPbHrk*/
x-"7{@lz
N4Ym[l
public FileAccessI(String sName,long nPos) throws IOException eWFlJ;=
{ JO$0Z
oSavedFile = new RandomAccessFile(sName,"rw"); X@ss d
this.nPos = nPos; Y\rKw!u_!
oSavedFile.seek(nPos); R .,w`<<
} y Le5,
:sf;Fq
ixp%aRRP
public synchronized int write(byte[] b,int nStart,int nLen) ;J4_8N-
{ `f(!i mN
int n = -1; *]rV,\z:
try{ TZ/u"' ZS
oSavedFile.write(b,nStart,nLen); "/q6E
n = nLen; wL{Qni3A
} _*+M'3&=
catch(IOException e) yO !*pC
{ h0GXN\xI
e.printStackTrace (); hAY_dM
} [=iq4F'7
}"szL=s
,HkJ.6KF
return n; |i|O9^*%
} u`ZnxD>
=Vi+wH{xM
, vR4x:W
} }\9qN!ol
Q5Wb)
*2[r?!
/* \d6A<(!=v
**SiteInfoBean.java {BF$N#7
*/ Dd*C?6
package NetFox; x[_+U4-/
Ft07>E$/Q^
0g1uM:;
public class SiteInfoBean { ej0q*TH.
D;Z\GnD
dfNNCPu]+
private String sSiteURL; //Site's URL Wg#>2)>
private String sFilePath; //Saved File's Path <h^vl-L>
private String sFileName; //Saved File's Name ZqSczS7uf
private int nSplitter; //Count of Splited Downloading File i6[Hu8
Ts.61Rx
7{p,<Uz<"U
public SiteInfoBean() |'Jz(dv[
{//nSplitter的缺省值为5 ^JH 4: h
//default value of nSplitter is 5 1vX97n<}
this("","","",5); 1v`*%95
} ?@tp1?)
V-VR+Ndz
QqRL>.)W
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i`X/d=
{ 1Ztoj}!I
sSiteURL= sURL; .8k9yk
sFilePath = sPath; O5E\#*<K
sFileName = sName; {`{U\w5Af
this.nSplitter = nSpiltter; R+P1 +5
`}18A.K
C}7Sh6
} O Qd,.m
59GS:
B lD
public String getSSiteURL() &)1+WrU
{ )!3sB{H
return sSiteURL; [/'W#x
} <"6}C)G
p?ICZg:
xse8fGs
public void setSSiteURL(String value) 8^kw
{ dtJ?J<m}
sSiteURL = value; {"-uaH>,
} 3b~k)t4R
J#MUtpPdQ
l7\Bq+Q
public String getSFilePath() I_\j05
{ ih~ R?W
return sFilePath; !?,rcgi
} 2Lm.;l4YO
ca5Ir<mL
L2+~I<|>
public void setSFilePath(String value) }qxwNmx
{ i,ga2{GnM
sFilePath = value; Ub3^Js!b%
} IvO#tI
Tw8$6KUW
g6MK~JG$?h
public String getSFileName() )ui]vS:>
{ eqV;4dhm
return sFileName; Y$ZZ0m
} 4~4D1
bs/Vn'CE
8!sl) R
public void setSFileName(String value) uS;N&6;:
{ M$ CnaH
sFileName = value; F@UbUm2o
} jhg0H2C8
#L ffmS
bu$YW'
public int getNSplitter() o-c.D=~
{ "=@X>jUc
return nSplitter; f<?v.5($
} MDAJ p>o
;Lr]w8d
B^nE^"b
public void setNSplitter(int nCount) *d b,N'rK
{ fgdqp8~
nSplitter = nCount; h8'`g 0
} bL-+
} dD ?ZF6
b*(74>XY
E+)3n[G
/* n 'gU
**Utility.java ir!/{IQx
*/ p?PK8GL
package NetFox; NCL!|
JS$ojL^
Cl&YN}t5
public class Utility { 2!QQypQ
Lh\ 1L
m9M#)<@*
public Utility() P:KS*lOp
{ 4MUN1/DId`
stQRl_('
VUmf;~
} cao=O \Y7
%?2y2O,;
//线程睡眠 lu vrvm
public static void sleep(int nSecond) l$/.B=]
{ F#=M$j_
try{ zl $mt'\y
Thread.sleep(nSecond); }JI@f14
} [0MNq]gxf
catch(Exception e) ?sD4S
{ OGcq]ue
e.printStackTrace (); 5v5)vv.kd
} 37<^Oly!
} %>Q[j`9y
Q?xA))0
//日志 [3D*DyQt
public static void log(String sMsg) s_o{w"3X
{ z;iNfs0i$
System.err.println(sMsg); V$0mcwH
} l$Y*ii
pT|l"q@
[eLMb)n
public static void log(int sMsg) x/NjdK
{ x4bmV@b
System.err.println(sMsg); ]}4JT
} G9_7jX*
} \~X:ffb =
#fy3i+
:_k5[KT.]9
/* X~g U$
**TestMethod.java T_)G5a
*/ -kzp>=
package NetFox; }i._&x`):
_$+BYK@
&8\6%C
public class TestMethod { ij5|P4Eka
Nnx dO0X
B_mT[)ut
public TestMethod() *[Im].
{ ///xx/weblogic60b2_win.exe rHiBW!
try{ F/ o }5H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ?[?;%Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;vG%[f`K
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7y4jk
fileFetch.start(); \&/V p`
} X6<Ds'I
catch(Exception e){e.printStackTrace ();} l#IN)">1
YJGP8
otA'+4\
} G4rd<V0[D
m`BE{%
|BBo
public static void main(String[] args) $+|. @ss
{ E5qt~:C|
new TestMethod(); IN_O!c0e
} Z H2
} }2h!
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