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)); #Dj"W8'zh
} ?Kx6Sf<i
for(int i=0;i<nEndPos.length-1;i++) 95.qAFB1
{ cW81
nEndPos = nStartPos[i+1]; G8^0^@o
} p|&ZJ@3
nEndPos[nEndPos.length-1] = nFileLength; _Hz~HoNU
} ? -v
} ,h%D4EVx
'2Q.~6
J<b3"wK0[
//启动子线程 RL7C YB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =F'l's^j
for(int i=0;i<nStartPos.length;i++) fbh6Ls/
{ olD@W UB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l?[{?Luq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), f pv= P
nStartPos,nEndPos,i); JYZ2k=zh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7>nhIp))
fileSplitterFetch.start(); +8LM~voB
} ,~?A,9?%:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), J-t=1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eVqM=%Q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", JDC=J(B
nEndPos = " + nFileLength); nwa\Lrh
// fileSplitterFetch[nPos.length-1].start(); ;yk9(wea}"
@wd!&%yzO
E/"YId `A
//等待子线程结束 ~pHJ0g:t
//int count = 0; h|J;6Sm@
//是否结束while循环 ]4Nvh\/P9
boolean breakWhile = false; ?8Hn{3X
]%gp?9wy
gIV3n#-{L
while(!bStop) D+| K%_Qq
{ HBt|}uZ?6i
write_nPos(); G"G{AS
Utility.sleep(500); SL[rn<x|
breakWhile = true; :wQC_;
??%)|nj.
U>/<6Wd
for(int i=0;i<nStartPos.length;i++) IY];Ss&i
{ bin6i2b
if(!fileSplitterFetch.bDownOver) R^jlEt\&P
{ GwgFi@itN
breakWhile = false; k-{yu8*';
break; 2-B6IPeI
} 9uA, +
} Y*5Z)h 1
if(breakWhile) 7ZS>1
break; UJ7'JBT=k
jK3giT
T$:>*
//count++; ?cqicN.+6
//if(count>4) gJ]Cq/gC
// siteStop(); DBQOxryP>o
} ?"()>PJx
oUl=l}qnD
X}3P1.n:
System.err.println("文件下载结束！"); ]WTf< W<
} hNH.G(l0
catch(Exception e){e.printStackTrace ();} *,E;
} kxwNbxC
eeZIa`.sX
K5P Gi#
//获得文件长度 p@#]mVJ>9
public long getFileSize() !nec 7
{ gE\A9L~b
int nFileLength = -1; IM@"AD52a
try{ W;^Rx.W
URL url = new URL(siteInfoBean.getSSiteURL()); "4'kb
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [<_"`$sm=
httpConnection.setRequestProperty("User-Agent","NetFox"); MB1sQReOO
4O$mR
pgCd
int responseCode=httpConnection.getResponseCode(); A ?#]s
if(responseCode>=400) #.~ga7Q
{ lo"j )Zt
processErrorCode(responseCode); +c-6#7hh
return -2; //-2 represent access is error uZ@-e|qto
} ksTzXG8
.6\T`6H=a
7raSf&{&6b
String sHeader; LEWa6'0rq
r])Z9bbi
nHrP>zN
for(int i=1;;i++) :_>\DJ'>
{ L_E^}^1!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); [}{w
//Utility.log(in.readLine()); I!61 K
sHeader=httpConnection.getHeaderFieldKey(i); )X7e$<SU*
if(sHeader!=null) :M@MmpPh
{ 64?Pfir6
if(sHeader.equals("Content-Length")) `+oV/:Q3
{ g4Y) Bz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k}X[u8A
break; /j11,O?72
} 9H>BWjS
} g8KY`MBnC&
else ,g%o
break; w-r_H!-
} Ft3I>=f{
} BlL|s=dlQV
catch(IOException e){e.printStackTrace ();} w2k<)3 g~
catch(Exception e){e.printStackTrace ();} -<xyC8$^$
B#1:Y;Z
dl:-k r8
Utility.log(nFileLength); it~Z|$
5bXHz5i
r)Or\HL
return nFileLength; WPtMds4
} J`W-]3S#
A1Ka(3"
"t=UX -3
//保存下载信息（文件指针位置） &D]&UQf
private void write_nPos() 5qC:yI
{ }X.>4\B5
try{ 3!>/smb!
output = new DataOutputStream(new FileOutputStream(tmpFile)); +yCTH
output.writeInt(nStartPos.length); mqdOu{kQ
for(int i=0;i<nStartPos.length;i++) '6O|H
{ MvBD@`&7
// output.writeLong(nPos); F,Q?s9s
output.writeLong(fileSplitterFetch.nStartPos); R'L?Xn}3
output.writeLong(fileSplitterFetch.nEndPos); {H+?z<BF<
} J,RDTXqn
output.close(); !I~C0u
} n3'dLJH|
catch(IOException e){e.printStackTrace ();} lw s(/a*c
catch(Exception e){e.printStackTrace ();} {$0&R$v3
} !Qcir&]C>
]Dh1~k.Kp
te)n{K",
//读取保存的下载信息（文件指针位置） 8`*`nQhWa
private void read_nPos() \2j|=S6
{ wrabyRjK
try{ ka#K [qI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t}VwVf<K
int nCount = input.readInt(); 6%E~p0)i%
nStartPos = new long[nCount]; nx B32
nEndPos = new long[nCount]; Q{[@`bZB
for(int i=0;i<nStartPos.length;i++) Lbsr_*4t
{ 9^au$KoU
nStartPos = input.readLong(); +>4^mE" \
nEndPos = input.readLong(); []"=]f{1};
} !9DX=?
input.close(); jQ?LHUE
} #sZIDn J#
catch(IOException e){e.printStackTrace ();} 1+a@k
catch(Exception e){e.printStackTrace ();} &Xv1[nByU
} ]rnXNn;
I(n }<)eF
p-,Iio+
private void processErrorCode(int nErrorCode) S.W^7Ap
{ ck$M(^)l
System.err.println("Error Code : " + nErrorCode); )km7tA 0a
} 8aZ$5^z
Pxqiv9D<R
=-Nsc1&
//停止文件下载 ;\x~'@
public void siteStop() wdwp9r
{ L7}i q0
bStop = true; nVXg,Jl
for(int i=0;i<nStartPos.length;i++) :Jk33 N4y0
fileSplitterFetch.splitterStop(); 7TpRCq#
(N0sE"_~I5
O:e#!C8^
} [x5mPjgw
} w4,]2Ccn.
//负责部分文件的抓取 [Tp%"f1
**FileSplitterFetch.java m6i%DE
*/ J(e7{aRJ9
package NetFox; iDw.i"b
&\^rQi/tf
U-g9C.
import java.io.*; yUe+":7k.
import java.net.*; =Dk7RKoHF
t8/%Dgu
yj zK.dM
public class FileSplitterFetch extends Thread { ~RInN+N#
@VK6JjIq
VoM6
String sURL; //File URL Sy
long nStartPos; //File Snippet Start Position 8teJ*sz
long nEndPos; //File Snippet End Position Y\(;!o0a
int nThreadID; //Thread's ID ezn` _x_?
boolean bDownOver = false; //Downing is over $P nLG]X
boolean bStop = false; //Stop identical 2+:'0Krc
FileAccessI fileAccessI = null; //File Access interface \[ M_\&GC
$;`I,k$0>~
=X@o@1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f-D>3qSS
{ p411 `]Zf
this.sURL = sURL; jct./arK
this.nStartPos = nStart; :Q7mV%%
this.nEndPos = nEnd; X;VQEDMPU
nThreadID = id; OH6n^WKY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .6m_>Y6
} f{ ^:3"i
iSiDSeW8
rwgsXS8W6
public void run() ,Sg33N?
{ opD-vDa h
while(nStartPos < nEndPos && !bStop) bX2"89{
{ 74f9|~%
LT_iS^&1
*_"u)<J
try{ 3sbK7,4
URL url = new URL(sURL); {G*OR,HN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h1f8ktF
httpConnection.setRequestProperty("User-Agent","NetFox"); QDE$E.a
String sProperty = "bytes="+nStartPos+"-"; !d8A
httpConnection.setRequestProperty("RANGE",sProperty); B+"g2Y
Utility.log(sProperty); MhxDV d
cAEokP
)yj:PY]
InputStream input = httpConnection.getInputStream(); ; )llt G
//logResponseHead(httpConnection); +pp9d-n
CVQB"L
_kN*e:t
byte[] b = new byte[1024]; W&C-/O,m
int nRead; Gx'TkU=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z0*%Rq
{ 3ZojE ux`
nStartPos += fileAccessI.write(b,0,nRead); <kbyZXV@K
//if(nThreadID == 1) KOSQQf o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;`UecLb#
} Yb:pAzw6
:(p)1=I
r}W2Ak\
Utility.log("Thread " + nThreadID + " is over!"); 8\Hr5FqB(
bDownOver = true; wC` R>)
//nPos = fileAccessI.write (b,0,nRead); 1mH\k5xu
} SlaDt
catch(Exception e){e.printStackTrace ();} CDdkoajBa
} -^SA8y
} |/T43ADW
?KP}#>Ba@
/k6fLn2;
//打印回应的头信息 6+`tn
public void logResponseHead(HttpURLConnection con) Yc;ec9~
{ n:4uA`Vg
for(int i=1;;i++) Z cpmquf8L
{ /3B6Mtb
String header=con.getHeaderFieldKey(i); 1%`7.;!i
if(header!=null) |B^G:7c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Vmi{X b]<
Utility.log(header+" : "+con.getHeaderField(header)); JhX=l-?
else yI)~]K r
break; VKW|kU7Cs$
} DtF}QvA
} D7?C
P8I*dvu _
zoZH[a`H
public void splitterStop() L CSeOR
{ YnTB&GPxl
bStop = true; /:[2'_Xl
} 0rE(p2
NlF}{
'q{733o
} Vrp[r *V@E
J4aBPq`
q_t4OrLr=
/* ?c#$dc"
**FileAccess.java ,pt%) c
*//文件访问(定位，写) 8;"*6vHZ
package NetFox; 0KvVw rWJ
import java.io.*; ,1UZv>}S
Qa`hR
IL!=mZ>2O
public class FileAccessI implements Serializable{ N[D\@o
&_x/Dzu!z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 2ZIY{lBe
RandomAccessFile oSavedFile; oL/^[TXjH
long nPos; K*i1! "w
4Xho0lO&
2n r UE
public FileAccessI() throws IOException \EfwS% P
{ 8@*|T?r
this("",0); Pj5#G0i%
} "+JwS
QZq9$;>dW
^XB8A=xi
public FileAccessI(String sName,long nPos) throws IOException '|R@k_nx
{ uTt:/gm
oSavedFile = new RandomAccessFile(sName,"rw"); 'ah0IYe
this.nPos = nPos; 7CN[Z9Y^}
oSavedFile.seek(nPos); aC6b})^
} Q]'!FmXf
<UL|%9=~
#\;w::
public synchronized int write(byte[] b,int nStart,int nLen) <;Z3 5{
{ a~TZ9yg+HL
int n = -1; 1KR|i"
try{ c\ *OId1{;
oSavedFile.write(b,nStart,nLen); 6OW-Dif^AG
n = nLen; `GWq3c5
} I*R$*/)
catch(IOException e) T1di$8
{ [$Bb'],k
e.printStackTrace (); YfU#kvE'
} io'Ovhf:
1}M.}G2u/
M\6v}kUY
return n; fb;"J+
} j}*+-.YF
q,&T$Tw
nv{4 U}&P
} ?zu{&aOX|
Y\|J1I,Z4
wKbymmG
/* F ;&e5G
**SiteInfoBean.java 9v2 ;
*/ ,e_#
package NetFox; 9X` QlJ2|
$3B?
O3: dOL/C
public class SiteInfoBean { VrxH6Y
PtOnj)Q
mIo7 K5z{
private String sSiteURL; //Site's URL w5jZI|
private String sFilePath; //Saved File's Path :L0W"$
private String sFileName; //Saved File's Name db~:5#*
private int nSplitter; //Count of Splited Downloading File `%p6i| _Q
LL [>Uu?Y
S>E.*]_
public SiteInfoBean() dhkpkt<G8
{//nSplitter的缺省值为5 1D6O=j\
//default value of nSplitter is 5 `p|vutk)U
this("","","",5); uJ[Vv4N%9
} V/e_:xECC
hspg-|R
n<*]`do,w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i@L2W>{P
{ qT @IY)e
sSiteURL= sURL; W F<V2o{k
sFilePath = sPath; #+k[[; 0
sFileName = sName; q+~CA[H5K
this.nSplitter = nSpiltter; 0g-ESf``{n
*, K \A
K67? d
} $uhDBmb
C<XDQ>?
U^\~{X
public String getSSiteURL() |vzWSm
{ F\bI6gj
return sSiteURL; q/79'>`|ai
} f*Js= hvO
zX`RN)C
/|AuI qW
public void setSSiteURL(String value) <Q)}
{ G9Tix\SpF
sSiteURL = value; &y\2:IyA
} g1,
*'-^R9dN.S
aS G2K0
public String getSFilePath() BwD1}1jp
{ V}+;bbUc-
return sFilePath; ^#se4qQ
} 8f5^@K\c
_B FX5ifK
Qpf]3
public void setSFilePath(String value) 1s[-2^D+EM
{ XtdLKYET
sFilePath = value; 7g+]
} \;gt&*$-
~1sl.8tF
l}c2l'
public String getSFileName() (OQ @!R&
{ rF3]AW(
return sFileName; rxeXz<
} 2tm-:CPG
LfXr(2u
|9Ks13?Ck
public void setSFileName(String value) =XlIe{
{ :=v{inN
sFileName = value; 6FMW g:{
} X.9MOdG70
ld:alEo
% ul{nL:
public int getNSplitter() OUO^/] J1S
{ pu*u[n
return nSplitter; z>;+'>XXgx
} G<6grd5PP
0(9@GIT
9$@ g;?}Ps
public void setNSplitter(int nCount) f<p4Pkv
{ Ltd?#HP
nSplitter = nCount; wD^do
} y$V)^-U>fw
} \+Ln~\Sv
05I39/T%
(H%d]
/* 9|A-oS
**Utility.java Cy:`pYxhd
*/ T&"dBoUq>G
package NetFox; 0W%}z}/N
Ss! 3{VW
dN/ "1%9)
public class Utility { ]O=S2Q
G,|]a#w&v.
2*wO5v
public Utility() VSpt&19
{ 'EET3RK-S
GKujDx+h
^~<Rzq!
} {F+M&+``
mQ60@_"Y=,
//线程睡眠 skDk/-*R
public static void sleep(int nSecond) hi D7tb=g~
{ 0ij~e<
try{ 0Q- Mxcj
Thread.sleep(nSecond); 2]aZe4H.
} ^&';\O@)
catch(Exception e) H;*a:tbxO+
{ Lr?4Y
e.printStackTrace (); K l0tyeT
} n]C%(v!u3
} VXc+Wm*W
ZG/8Ds
//日志 U|Z>SE<k
public static void log(String sMsg) PVD ~W)0m*
{ O? Gl4_y
System.err.println(sMsg); gAr`hXO
} `f6)Q`n
bxhg*A
[cQ<dVaTX
public static void log(int sMsg) Y!= k
{ 0ve`
System.err.println(sMsg); k$-~_^4m
} -q&7J' N
} LE<u&9I\
^#BGA|j
gVnwsE
/* x>^3]m
**TestMethod.java b$goF }b'g
*/ ne"?90~
package NetFox; O@r.>
o4/I1Mq
+=6RmId+X
public class TestMethod { i[2bmd!H
xI@$aTGq
YXX36
public TestMethod() rQcRjh+E H
{ ///xx/weblogic60b2_win.exe +^4BO`
try{ BSfm?ku"!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); fou_/Nrue
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =&q-[JW
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~[|V3h4v
fileFetch.start(); :Su#xI
} g|K6iY
catch(Exception e){e.printStackTrace ();} @e!Zc3
x)ddRq l
pHen>BA[
} UCn*UX
^)f{q)to
axK6sIxx
public static void main(String[] args) n+{HNr
{ %RQC9!
new TestMethod(); c=A(o
} ?Oy'awf_
} eg"=H50
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