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)); NzbHg p
} MDfC%2Q
for(int i=0;i<nEndPos.length-1;i++) u{|^5%)
{ QVWUm!
nEndPos = nStartPos[i+1]; +aRHMH
} X/23 /_~L`
nEndPos[nEndPos.length-1] = nFileLength; &5R-bYGW
} y_{v&AGmgm
} &(~"OD
3 /LW6W|
|JTDwmR
//启动子线程 Tywrh9[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g715+5z[
for(int i=0;i<nStartPos.length;i++) "mAMfV0
{ VPOp#;"%
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VBe&of+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }1Pv6L(o)
nStartPos,nEndPos,i); jW]Fx:mQi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P.O/ZW>g
fileSplitterFetch.start(); 0]l9x}
} BDPF>lPf<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vPx#TXY=b}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;f2<vp;U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", CV*
nEndPos = " + nFileLength); 2yndna-
// fileSplitterFetch[nPos.length-1].start(); $ZnVs@:S
G/V0Yn""
/4,U@s)"/
//等待子线程结束 n$ZxN"q <
//int count = 0; Xh`Oin}<
//是否结束while循环 RzqU`<//
boolean breakWhile = false; 6('xIE(R
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yeN(_t2.
while(!bStop) #,rP1#?
{ 8PvO_Gz5
write_nPos(); u1/q8'RW
Utility.sleep(500); 420cbD3a
breakWhile = true; 4j~WrdI*
A|BN>?.t
WmZ,c_
for(int i=0;i<nStartPos.length;i++) *5R91@xt
{ c_syJ<
if(!fileSplitterFetch.bDownOver) y?8V'.f|
{ Fzn#>`qG
breakWhile = false; _)^`+{N<
break; seNH/pRb
} qF4DX$$<
} _H$Z}2g<z
if(breakWhile) )Tad]Hd"W
break; K?,`gCN}v
Hv|(V3-
{fu[&@XV
//count++; ufS0UD8%H
//if(count>4) hPrE
// siteStop(); n16TQe"8
} *ZF:LOnU
s:Z1 ZAxv
mp17d$R-
System.err.println("文件下载结束！"); 3H,>[&d
} )-S;j)(+
catch(Exception e){e.printStackTrace ();} T%1Kh'92
} 5 OF*PBZ
q??N,
Ox+}JB [
//获得文件长度 ( ALsc@K
public long getFileSize() `-<m#HF:)d
{ 8:}$L)[V
int nFileLength = -1; 3vF-SgCV
try{ " {Nw K
URL url = new URL(siteInfoBean.getSSiteURL()); S{qn^\0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "gq_^&
httpConnection.setRequestProperty("User-Agent","NetFox"); qN6GLx%
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int responseCode=httpConnection.getResponseCode(); B-aJn8>/
if(responseCode>=400) Axx{G~n![
{ Xe\,:~
processErrorCode(responseCode); kF7`R4Sz
return -2; //-2 represent access is error ,4kipJ!,yK
} QlWkK.<Z3_
?+y# t?
pt8#cU\
String sHeader; 7'TXR[
g<N3 L[
$ iU~p
for(int i=1;;i++) ;q" ,Bs
{ > V%3w7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vX"jL
//Utility.log(in.readLine()); gj1l9>f>]a
sHeader=httpConnection.getHeaderFieldKey(i); 1A/li%
if(sHeader!=null) D[CEg2$y
{ He)dm5#fg
if(sHeader.equals("Content-Length")) UQ)7uYQ5
{ ;X[23A{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R=s^bYdoy
break; Rj{D#5
} QD*(wj
} -vBk,;^>
else -Khb
break; }J\KnaKo
} 8:t1%O$
} %'<m[wf^ o
catch(IOException e){e.printStackTrace ();} kNTxYJ
catch(Exception e){e.printStackTrace ();} R3} Z"
aW#_"Y}v'
m4kUA"n5
Utility.log(nFileLength); ^tKJ}}
K9f7,/
%TRH,-@3h
return nFileLength; n"Q fW~U
} [:C!g#o
Xu&4|$wB+
MA5BTq<&
//保存下载信息（文件指针位置） ?3Dsz
private void write_nPos() vCtag]H2@
{ }-ysP$
try{ zj9aaZ}
output = new DataOutputStream(new FileOutputStream(tmpFile)); N^&T5cAC
output.writeInt(nStartPos.length); NuKx{y}P
for(int i=0;i<nStartPos.length;i++) oi}\;TG
{ `(?x@Y>.Ht
// output.writeLong(nPos); {"w4+m~+te
output.writeLong(fileSplitterFetch.nStartPos); |&a[@(N:zf
output.writeLong(fileSplitterFetch.nEndPos); ^)|1T#Tz
} bLi>jE.%.
output.close(); p3(&9~s
} }9ZcO\M
catch(IOException e){e.printStackTrace ();} 5T;,wQ<
catch(Exception e){e.printStackTrace ();} cE0Kvqe`
} Ok2>%e
YC0FXNV
*FEY"W+bY
//读取保存的下载信息（文件指针位置） 9Fm><,0'u
private void read_nPos() 'HDbU#vD
{ .]W A/}
try{ Uw5`zl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^YG.eT6iG
int nCount = input.readInt(); Ws(#ThA
nStartPos = new long[nCount]; 3Q"4-pd
nEndPos = new long[nCount]; k,nRC~Irh
for(int i=0;i<nStartPos.length;i++) K# dV.
{ 0q ^dpM
nStartPos = input.readLong(); +R?d6IjH
nEndPos = input.readLong(); _K"X
} Dx<CO1%z-
input.close(); :X;AmLf`2u
} /IN/SZx
catch(IOException e){e.printStackTrace ();} sd~T
catch(Exception e){e.printStackTrace ();} RW. >;|m
} /K]<7
oZ(T`5
{|J'd+
private void processErrorCode(int nErrorCode) E64d6z^7u
{ /^z5;aG
System.err.println("Error Code : " + nErrorCode); wFJ?u?b0Q
} lfp'D+#p{
<e&*Tx<8
4aQb+t,
//停止文件下载 "?Cx4<nsM
public void siteStop() ?=h{`Ci^ $
{ p4OiCAW;
bStop = true; ndIU0kq3
for(int i=0;i<nStartPos.length;i++) ;eRYgC
fileSplitterFetch.splitterStop(); "*E%?MG
icPg<>TQ
SlZ>N$E
} T=QV =21qn
} =pP0dvn
//负责部分文件的抓取 /)` kYD6
**FileSplitterFetch.java q0hg0DC[;
*/ )} H46
package NetFox; yS[Z%]bvU
2nRL;[L*.
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import java.io.*; VfiMR%i}
import java.net.*; NN9`jP2
H `V3oS~}
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public class FileSplitterFetch extends Thread { ]7, mo
6DG:imGl
'B>%5'SdD
String sURL; //File URL p ft6 @'q
long nStartPos; //File Snippet Start Position 1wa zJj=v
long nEndPos; //File Snippet End Position >"Z^8J
int nThreadID; //Thread's ID bstc|8<
boolean bDownOver = false; //Downing is over @{Q[M3l
boolean bStop = false; //Stop identical u9*}@{,
FileAccessI fileAccessI = null; //File Access interface +0Rr5^8u
0/."R;
;_lEu" -
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x_oL~~@
{ t4H@ZvAH0
this.sURL = sURL; |QvG;{!
this.nStartPos = nStart; {<HL}m@kQ
this.nEndPos = nEnd; 6"Km E}
nThreadID = id; _ s]=g
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0NB6S&lI^k
} GP5Y5)
MhNDf[W>
=;/4j'1}9
public void run() bV#U&)|
{ "3*Chc
while(nStartPos < nEndPos && !bStop) y4HOKJxI
{ D %`64R
D/w4u;E@
?5qo>W<7
try{ 2@ >04]
URL url = new URL(sURL); T7AFL=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /]Fs3uf
httpConnection.setRequestProperty("User-Agent","NetFox"); *@q+A1P7@
String sProperty = "bytes="+nStartPos+"-"; QM1-w^
httpConnection.setRequestProperty("RANGE",sProperty); |yi3y `f
Utility.log(sProperty); Ok+zUA[Wu
9K@>{69WQ
FBM 73D@`
InputStream input = httpConnection.getInputStream(); T{={uzQeJJ
//logResponseHead(httpConnection); u":D{+wC|
^IxT.g
B8^tIq
byte[] b = new byte[1024]; ,*2%6t`N?
int nRead; UlHRA[SCv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zv]-(<B
{ iAX\F`
nStartPos += fileAccessI.write(b,0,nRead); j w)Lofn
//if(nThreadID == 1) ~a[]4\m;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YWSo:)LY
} pCz;km
"msCiqF{z
Tw{H+B"uVz
Utility.log("Thread " + nThreadID + " is over!"); ,#1ke
bDownOver = true; WYQJ+z5
//nPos = fileAccessI.write (b,0,nRead); FX"%
} bh&,*Y6=
catch(Exception e){e.printStackTrace ();} @^y/V@lDm
} *hAeA+:
} GqI^$5?
2hV#3i
{4 !%'~
//打印回应的头信息 22\Buk}?
public void logResponseHead(HttpURLConnection con) FDaHsiI:
{ C+Wb_
for(int i=1;;i++) "aN<3b
{ GdavCwJ
String header=con.getHeaderFieldKey(i); jK#y7E
if(header!=null) .*>LD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~4[2{M.0>@
Utility.log(header+" : "+con.getHeaderField(header)); v.)'be*u
else ~ X8U@f
break; Y;je::"
} R0;c'W)
} a}a_&rf~Z
YNbs*i&
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public void splitterStop() +vkqig
{ a\\B88iRRZ
bStop = true; d3T|N\(DL
} (|Am
}$V]00 X
5j`"@C5;O
} l/yLSGjM
EA2BN}
|H5){2V>K
/* rd\mFz-SB
**FileAccess.java []0`>rVq
*//文件访问(定位，写) 6hYv
package NetFox; 2](R}
import java.io.*; !&TbE@Xk
U KF/v
.9> er
public class FileAccessI implements Serializable{ z.eqOPW
+DM+@F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 B_M)<Ad
RandomAccessFile oSavedFile; bslv_OxJ
long nPos; jHBn^Nly
3S:}fPR
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public FileAccessI() throws IOException \SnW(,`oX
{ 3mZX@h@
this("",0); O{&5/xBA
} %,MCnu&Z
4pkc9\
F&;g< SD
public FileAccessI(String sName,long nPos) throws IOException dW<.
{ oo3ZYA
oSavedFile = new RandomAccessFile(sName,"rw"); x2/|i?ZO
this.nPos = nPos; 3j0/&ON
oSavedFile.seek(nPos); P6S^wjk
} <(?ahO5
jt tlzCDn
<8!mmOK1
public synchronized int write(byte[] b,int nStart,int nLen) N2;T\xx,
{ |A7Yv
int n = -1; :D-d`OyjG>
try{ Ka2U@fK"
oSavedFile.write(b,nStart,nLen); `8\pihww
n = nLen; QY-P!JD
} >Fz_]z
catch(IOException e) b`E0tZcJ
{ gPe*M =iF
e.printStackTrace (); 0gHJ%m9s
} w@.E}%bwq
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b0x9}
return n; Xgd!i}6Q
} {8Hrb^8!
wlC_rRj~
qDhz|a#
} }Q`Kg8L
;f[Ki$7
6*kY7
/* Mc~(S$FU$
**SiteInfoBean.java nq8mzI
*/ XV)ej>A-V
package NetFox; t3 *2Z u
}{:H0)H*
f&H):.
public class SiteInfoBean { >AV-i$4eQ@
xv's52x
s}`ydwSg8
private String sSiteURL; //Site's URL w@nN3U+
private String sFilePath; //Saved File's Path ;_of'
private String sFileName; //Saved File's Name waQNX7Xdn
private int nSplitter; //Count of Splited Downloading File c_O|?1
QgEG%YqB
bL!NT}y`
public SiteInfoBean() f'aUo|^?
{//nSplitter的缺省值为5 "2 ma]Ps
//default value of nSplitter is 5 R"!.|fH6
this("","","",5); +=|Q'V
} nO$(\ z)
U[c,cdA
x<P$$G/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) j3P)cz-0/L
{ er,R}v
sSiteURL= sURL; "Hg.pDNZ
sFilePath = sPath; :bW}*0b-
sFileName = sName; ]Tf.KUm
this.nSplitter = nSpiltter; mDvZ1aj
KZ`d3ad
{_ww1'|A
} Bg"b,&/^u
\UGs_5OT
aIRCz=N
public String getSSiteURL() * ?rw'
{ Xl2Fgg}#
return sSiteURL; y{s?]hLk
} 1*[h$Z&H?
TPq5"mco
b3H~a2"d
public void setSSiteURL(String value) t=~al8
{ JQ%e'
sSiteURL = value; I^[R]Js
} /o.wCy,J<
E[Tz%x=P
HpSgGhL'J&
public String getSFilePath() ]b.@i&M
{ #|GP]`YT
return sFilePath; z~A||@4'
} <!Nj2>
rV"<1y:g
,@/b7BVv
public void setSFilePath(String value) `U#*O+S-^
{ PGP9-M
sFilePath = value; 2!-ZNd:(+
} LP7t*}PK
C=h$8Q
Dsm_T1X
public String getSFileName() )j4]Y dJ
{ %8yfFrk
return sFileName; ?Re@`f+*
} vZTX3c:,1
s)_7*DY
6QLWF@
public void setSFileName(String value) ?<#6=
{ rfkk3oy
sFileName = value; dum! AO
} YCj"^RC^
?2 u_E "
Gz+Bk5#{
public int getNSplitter() Cl6y:21]K
{ 1[[` ^v
return nSplitter; u<]-%ha$
} TCX*$ac"
8,a&i:C
ot;j6eAH~E
public void setNSplitter(int nCount) XGFU *g`kq
{ d~D<;7M XJ
nSplitter = nCount; z/.x*A=
} =mn)].Wg
} @8HTC|_vX
5MQD:K2
!\}Dxt
/* ]~U4;
**Utility.java ]chcRc[!
*/ fS>W-
package NetFox; W7WHH \L/O
oR[,?qu@f
;? '`XB!
public class Utility { %q;3bfq@N
R."<he ;
{[jcT>.3j
public Utility() 5H6m{ng
{ 0F1 a
drBWo|/
`a["`N^
} hWJ\dwF
z. VuY3
//线程睡眠 YKJk)%;+w
public static void sleep(int nSecond) <dV|N$WV
{ z;zyk
try{ sw[1T_S>
Thread.sleep(nSecond); L oe!@c
} o*_[3{FU
catch(Exception e) ^W eE%"
{ al F*L
e.printStackTrace (); GLB7h9>
} 9jDV]!N4
} +6B(LPxgP
\tye:!a?;@
//日志 I?G m
public static void log(String sMsg) H~i+:X=I
{ 8v8?D8\=|
System.err.println(sMsg); 5,:>.LRA
} 4rO07)~l
>DBaKLu\
]ctUl#j
public static void log(int sMsg) ]!d #2(
{ MOP/q4j[
System.err.println(sMsg); 'VS!<
} lE78Yl]
} x>A(016:C
/1zi(z
\L}Soe'
/* B# |w}hj
**TestMethod.java $ii/Q:w T"
*/ gGxgU$`#c
package NetFox; "diF$Lj
`J|bGf#
|#D3~au
public class TestMethod { Dkayk
EA7 8&
7"yA~e,l
public TestMethod() skh6L!6*<
{ ///xx/weblogic60b2_win.exe b/:9^&z
try{ v?,_SVgAi
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G%Hr c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); "a6[FqTs
SiteFileFetch fileFetch = new SiteFileFetch(bean); \sEq r)\k
fileFetch.start(); SQDllG84E
} jutEb@nog
catch(Exception e){e.printStackTrace ();} c/DB"_}!a
0.'$U}#b
z2vrV?:
} OIGu`%~js
-GLI$_lLF
n2zJ'
public static void main(String[] args) 26B]b{Iz{
{ =H%c/Jty
new TestMethod(); g,h'K
} Wz)s#
} _Jx.?8
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