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)); :<|Z.4}kJb
} [UoqIU
for(int i=0;i<nEndPos.length-1;i++) mH)OB?+lq
{ GMBJjP&R]
nEndPos = nStartPos[i+1]; /jR8|sb
} }t\ 10nQ
nEndPos[nEndPos.length-1] = nFileLength; ?~,JY
} gwiR/(1
} 8'KMxR
iX{H,-C
fWj@e"G
//启动子线程 X@!X6j
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; G]-%AO{K
for(int i=0;i<nStartPos.length;i++) 7%4.b7Q
{ 45)D+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qwv '<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9\AS@SH{^T
nStartPos,nEndPos,i); wlrIgn%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VG)="g[%)
fileSplitterFetch.start(); uJY.5w
} S6GMUaR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #&V5H{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [t{](-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kbhX?; <`
nEndPos = " + nFileLength); x6ahZ
// fileSplitterFetch[nPos.length-1].start(); 9<l-NU9 _
Zi/-~')E
6 Uw;C84!
//等待子线程结束 ^!}F%
//int count = 0; iS
//是否结束while循环 _s*! t
boolean breakWhile = false; ra]:$XJ5=a
7/?DPwbx
Y%g "Y
while(!bStop) V9T 4+
{ N<liS3>
write_nPos(); K_>/lirE?
Utility.sleep(500); y@A6$[%(E|
breakWhile = true; ^X&)'H
B'p5M.6d#:
b66R}=P l
for(int i=0;i<nStartPos.length;i++) < eQ[kM
{ 5mavcle{4r
if(!fileSplitterFetch.bDownOver) nhewDDu
{ Hd0Xx}3&
breakWhile = false; 3D[=b%2\
break; O:JPJ"!
} (B:uc_+
} {2:d`fqD
if(breakWhile) (;UP%H>
break; +i=p5d5
C8.W5P[U
e!Br>^8l
//count++; JT)k
//if(count>4) x> \Bxa8
// siteStop(); rz.IoQo
} 3]^'
<Oa9oM},d
$)*xC!@6X
System.err.println("文件下载结束！"); TKOP;[1h
} <tuS,.
catch(Exception e){e.printStackTrace ();} Dx3%KS
} c&*l"
hk} t:<
5 `=KyHi:b
//获得文件长度 t77'fm
public long getFileSize() Ea]T>4
{ v459},!P
int nFileLength = -1; Q]#Z9H
try{ + |C=ZU
URL url = new URL(siteInfoBean.getSSiteURL()); ^f|<R8`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -~O/NX
httpConnection.setRequestProperty("User-Agent","NetFox"); V#J"c8n
RZh}:
X+iK<F$
int responseCode=httpConnection.getResponseCode(); &@6 GI<
if(responseCode>=400) g$w6kz_[
{ A(+:S"|@
processErrorCode(responseCode); Hf%_}Du /`
return -2; //-2 represent access is error e+@xsn3
} QNArZ6UQ
,|pp67
t$ZkdF
String sHeader; J3=BE2L
J=*K"8Qr
)GJP_*Ab
for(int i=1;;i++) v[&'k\
{ ,I`_F,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ^|?1_r
//Utility.log(in.readLine()); ?3jdg]&
sHeader=httpConnection.getHeaderFieldKey(i); HO5d%85
if(sHeader!=null) G),db%,X2
{ Yy h=G
if(sHeader.equals("Content-Length")) Hku=pr3Gn
{ 4RQ5(YTTuR
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /{X_ .fv<v
break; ]:et~pfW
} k1fRj_@WPT
} w>vH8f
else KlUqoJ;"
break; d#\W hRE
} "2;N2=~7
} C9jbv/c
catch(IOException e){e.printStackTrace ();} 0H[LS
catch(Exception e){e.printStackTrace ();} T~J?AKx
*Jt8
?9e]
Utility.log(nFileLength); }bMWTT
J+Bdz6lt
IN^_BKQt
return nFileLength; V@Wcb$mgk
} #DUh(:E'`
|C D}<r(N
nwf7M#3d
//保存下载信息（文件指针位置） 4#:\?HAu!
private void write_nPos() ~NNv>5t5
{ (WE,dY+.
try{ wiE]z
output = new DataOutputStream(new FileOutputStream(tmpFile)); yd>}wHt
output.writeInt(nStartPos.length); ?/d!R]3
for(int i=0;i<nStartPos.length;i++) wL2XNdo}<
{ l!IGc:
// output.writeLong(nPos); ``9 GY
output.writeLong(fileSplitterFetch.nStartPos); ^,V[nfQR
output.writeLong(fileSplitterFetch.nEndPos); Q4wc-s4RN
} q#vlBL
output.close(); ,%hj cGX11
} };sMU6e
catch(IOException e){e.printStackTrace ();} <*Y'lV
catch(Exception e){e.printStackTrace ();} GBbhar},g
} 5@P-g
]0/p 7N14
]MAT2$"le
//读取保存的下载信息（文件指针位置） IKcKRw/O$
private void read_nPos() ;fGx;D
{ (M`|'o!
try{ Oh`2tc-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (X}@^]lpa
int nCount = input.readInt(); T~s}Nx#
nStartPos = new long[nCount]; yVS\Q,:J9
nEndPos = new long[nCount]; FT/amCRyT
for(int i=0;i<nStartPos.length;i++) HC7JMj
{ cOku1g8
nStartPos = input.readLong(); zj%cQkZ
nEndPos = input.readLong(); \+Y!ILOI
} GDPo`#~
input.close(); HFS+QwHW
} jvs[ /
catch(IOException e){e.printStackTrace ();} rAXX}"l6s
catch(Exception e){e.printStackTrace ();} #D)x}#V\
} }.{}A(^YR
9;KJr[FQV
j|K.i/
private void processErrorCode(int nErrorCode) &U&%ka<*
{ iZ;TYcT
System.err.println("Error Code : " + nErrorCode); np6HUH
} ~L4eZ
D;js.ZF
Y\?j0X;
//停止文件下载 0ar=cuDm
public void siteStop() |F!F{d^p
{ ^l!L)iw
bStop = true; CV^c",b_
for(int i=0;i<nStartPos.length;i++) `="v>qN2\
fileSplitterFetch.splitterStop(); AS;.sjgk
G|9B)`S
z{?4*Bq
} J_xG}d
} T:!MBWYe|
//负责部分文件的抓取 2k1aX~?
**FileSplitterFetch.java QnKC#
*/ K/Y Agg
package NetFox; BUC,M:J+H
tWD|qg_
V(mnyI
import java.io.*; xb$yu.c
import java.net.*; $']VQ4tZ
kh?. K#
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public class FileSplitterFetch extends Thread { fp&Got!pB
L11L23:
.JAcPyK^
String sURL; //File URL /f3m)pT
long nStartPos; //File Snippet Start Position s AE9<(g&@
long nEndPos; //File Snippet End Position vA-PR&
int nThreadID; //Thread's ID nGa1a
boolean bDownOver = false; //Downing is over 8wIK:
boolean bStop = false; //Stop identical crn k|o
FileAccessI fileAccessI = null; //File Access interface ybvI?#
]T^is>
oR %agvc^^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException a%K}j\M
{ |:2c$zq
this.sURL = sURL; +ld;k/
this.nStartPos = nStart; KQ)T(mIqp
this.nEndPos = nEnd; N@1p]\
nThreadID = id; j Z'&0x"U
fileAccessI = new FileAccessI(sName,nStartPos);//定位 - L~Uu^o
} 0HbJKix!
<abKiXA"
a[C&e,)}
public void run() "!q?P" @C
{ bK=c@GXS
while(nStartPos < nEndPos && !bStop) Y';>O`
{ !_^g8^>2(
Y4To@TrN#\
Z"tQpJg
try{ qrDcL>Hrn
URL url = new URL(sURL); /`+7_=-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *K)0UKBr
httpConnection.setRequestProperty("User-Agent","NetFox"); 4e9E' "8%
String sProperty = "bytes="+nStartPos+"-"; 8:{q8xZ=k
httpConnection.setRequestProperty("RANGE",sProperty); tWk{1IL
Utility.log(sProperty); zM59UQU;
.#!mDlY;
,- HIFbXx@
InputStream input = httpConnection.getInputStream(); 9X]f[^
//logResponseHead(httpConnection); V/bH^@,sA
IJPgFZ7
[ud|dwP"
byte[] b = new byte[1024]; .,mPdVof
int nRead; ']?=[`#NL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8"M<{72U]
{ p\S8oHWe
nStartPos += fileAccessI.write(b,0,nRead); `C'}e
//if(nThreadID == 1) e1P7 .n}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7a<_BJXx
} B||c(ue
(6k>FSpg
\_ -DyD#3
Utility.log("Thread " + nThreadID + " is over!"); F]5\YYXO
bDownOver = true; re uYTH
//nPos = fileAccessI.write (b,0,nRead); D[~}uZ4\
} ;$;rD0i|
catch(Exception e){e.printStackTrace ();} tpU D0Z)
} ou6j*eSN
} [g|Hj)(
v@_in(dk
@^CG[:|
//打印回应的头信息 {!=2<-Aq
public void logResponseHead(HttpURLConnection con) ;3UvkN
{ 3;y_mg
for(int i=1;;i++) E@pFTvo
{ F=i!d,S
String header=con.getHeaderFieldKey(i); NI\H \#bJ
if(header!=null) xF8 :^'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /=ylQn3 *
Utility.log(header+" : "+con.getHeaderField(header)); (C`@a/q
else RVP18ub.S
break; 1+^n!$
} $L&BT 0
} AbZ:(+@cP
%6]\^
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public void splitterStop() +/q0Y`v
{ yW>RRE;
bStop = true; J3&Sj{ o
} QUp?i
@?/\c:cp
DV,DB\P$
} Jvj=I82
{^wdJZ~QLK
rfTe
/* XnY"oDg^>
**FileAccess.java J wFned#T
*//文件访问(定位，写) o?dR\cxj
package NetFox; la702)N{
import java.io.*; PP-kz;|
xt))]aH
D3.VXuKn6
public class FileAccessI implements Serializable{ 8.2`~'V
g)cY\`&W8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s##Ay{
RandomAccessFile oSavedFile; ]ymC3LV]
long nPos; .K7C-Xn=
6Ahr_{
7TdQRB
public FileAccessI() throws IOException 0||F`24
{ Ilef+V^qr
this("",0); p`p?li
} k<Oy%+C
%M6 c0d[9-
C8MWIX}
public FileAccessI(String sName,long nPos) throws IOException jGiw96,Y
{ 4:`[qE3
oSavedFile = new RandomAccessFile(sName,"rw"); raHVkE{<
this.nPos = nPos; 2Oi'E
oSavedFile.seek(nPos); /.v_N%*-v
} >)y$mc6
YkI9d&ib+
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public synchronized int write(byte[] b,int nStart,int nLen) 97]4 :Zv
{ Y?t2,cm
int n = -1; `EVg'?pl
try{ H9E(\)@
oSavedFile.write(b,nStart,nLen); R8uj3!3^
n = nLen; `WlH*p)z9
} *|poxT G
catch(IOException e) InN{^uN
{ cD8Ea(
e.printStackTrace (); @T/qd>T o
} P57GqT
m9Il\PoTq
-p^'XL*Z
return n; P'F~\**5
} g8v[)o(qd
P4[]qbfd,
@it/$>R^)
} yU!GS-
{\Ys@FF
@E(P9zQ/zy
/* V" }*"P-%
**SiteInfoBean.java 6lZGcRO
*/ _'lmCj8L
package NetFox; p2^)2v
j%u8=
$^IjFdD
public class SiteInfoBean { ,P~QS
!U[:5@s06
Pv[ykrm/
private String sSiteURL; //Site's URL 2_.CX(kI
private String sFilePath; //Saved File's Path L?Tu)<Mn
private String sFileName; //Saved File's Name kz_M;h>
private int nSplitter; //Count of Splited Downloading File kkL(;H:%
F~'sT}A*
B6uRJcD4
public SiteInfoBean() !^-OfqIHfV
{//nSplitter的缺省值为5 ]f5c\\)
//default value of nSplitter is 5 &~}@u[=ux
this("","","",5); vgN@~Xa
} fOLnK y#
W W35&mI)k
F#KF6)P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) [brkx3h
{ G}q<{<+$
sSiteURL= sURL; `xGT_0&ck
sFilePath = sPath; \eT/%$
sFileName = sName; 3wo'jOb
this.nSplitter = nSpiltter; nAvs~J
Cg7)S[zl
c~37+^B:
} B/rzh? b
N:7.:Yw
3jS7 uU
public String getSSiteURL() &rcdr+'
{ s4N,^_j
return sSiteURL; xlk5Gob*
} ;8uHRcdQ
A`g.[7
-FaaFw:Z;A
public void setSSiteURL(String value) :k\}Ik
{ <oQ6ZX
sSiteURL = value; IBDVFA
} lj Y
"5y<G:$+~
~Z7)x7 z
public String getSFilePath() T"IW Jpc
{ PH[4y:^DN
return sFilePath; 0+rW;-_(
} ^SgN(-QH
y%JF8R;n
m+p4Mc%u
public void setSFilePath(String value) ~RAzFLt6x
{ $Q=$?>4U
sFilePath = value; x~%\y
} 0:jsV|5B8
=I7[L{+~Y
L-j/R1fTvl
public String getSFileName() y>4p~
{ 7WXiG0
return sFileName; pTN%;`) {
} xS-w\vbLV
b#e]1Q
@PKAz&0
public void setSFileName(String value) \6U 2-m'
{ 1T:)Zv'
sFileName = value; DhHtz.6
} N-Qu/,~+
x4@MO|C
Cy]"
public int getNSplitter() a$A2IkD
{ xJ$Rs/9C
return nSplitter; haN"/C^
} B5D3_iX]
9#ZzE/
:J<Owh@
public void setNSplitter(int nCount) 8qn{
{ g~eJ YS,
nSplitter = nCount; e#K rgUG
} L(W%~UGN V
} K6ciqwUO
\MF3CK@/
]Qh[%GD
/* $3lt{ %
**Utility.java t$tsWAmiA[
*/ ' l|41wxk
package NetFox; dvC0 <*V
ex{)mE4Cd
Fka1]|j9
public class Utility { k>7gy?Y!K<
g9M')8a n
b$PT_!d
public Utility() C3]\$
{ }klE0<W|5\
| pF5`dX
v`@5enr
} ?.]o_L_K
i-|/2I9%
//线程睡眠 ,xm;JXJ
public static void sleep(int nSecond) )-MA!\=<
{ zuK/(qZ
try{ z]'|nX
Thread.sleep(nSecond); -$'~;O3s
} 3csm`JVK
catch(Exception e) M-{b
{ vd2uD2%con
e.printStackTrace (); Q@PJ)fwN
} oH!$eAU?
} `i"$*4#<
Z|V"8jE
//日志 MA~|y_V
public static void log(String sMsg) H(
{ =1%zI%
System.err.println(sMsg); iK$Vd+Lgc
} f6keWqv<GW
JsZAP
%@M00~-
public static void log(int sMsg) AGw1Pl8]K
{ |Ba4 G`
System.err.println(sMsg); 3?a0 +]
} @m*&c*r
} |#Yu.c*
tI/mE[W
x.jYip
/* Ukk-(gjX
**TestMethod.java UchALR^5
*/ i{Y=!r5r
package NetFox; K,`).YK
IKNFYe[9e
Jnh;;<
public class TestMethod { =;~%L
z^gDbXS
W}#QKZ)MB
public TestMethod() G%V=idU*"
{ ///xx/weblogic60b2_win.exe EuR!yD
try{ 1puEP*P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;oN{I@}k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U89]?^|bb
SiteFileFetch fileFetch = new SiteFileFetch(bean); :F!dTD$
fileFetch.start(); EM>c%BH<N
} eONeWY9
catch(Exception e){e.printStackTrace ();} .y/NudD
SX1Fyy6 w
T! &[
} rahHJp.Ws
.{'Uvn
[[Jv)?jm
public static void main(String[] args) o$[a4I
{ .ruz l(6
new TestMethod(); rw}5nv
} qv ;1$
} ')1}#V/I
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