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)); CSL#s^4T
} >1 @Ltvm
for(int i=0;i<nEndPos.length-1;i++) Y\xUT>(J7
{ _\.{6""
nEndPos = nStartPos[i+1]; s5l3V2k
} =SAV|
nEndPos[nEndPos.length-1] = nFileLength; o(*F])d;
} "PMQyzl
} *8bK')W
f~=r*&U
f1mHN7hxW
//启动子线程 A\z`c e!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8eluO ?p
for(int i=0;i<nStartPos.length;i++) -v+&pG?m
{ `>6T&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M;+IZr Wkl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +4et7
nStartPos,nEndPos,i); 2j&v;dmh<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F8<"AI
fileSplitterFetch.start(); g5+7p@'fV
} a(;!O}3_)(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *5k+t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a?F!,=F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }7ehF6
nEndPos = " + nFileLength); m:uPEpcU
// fileSplitterFetch[nPos.length-1].start(); rn8cdMN
+r]zs^'
hmpr%(c`
//等待子线程结束 n[,XU|2
//int count = 0; C&+6>L@
//是否结束while循环 Ipe n
boolean breakWhile = false; -)v@jlg02
w##^}nHOR
${I*nh>=
while(!bStop) ?>$l
{ #Exp51
write_nPos(); ***a2Z/(
Utility.sleep(500); aI3CNeav
breakWhile = true; eF~dQ4RZ
NBYH;h P
Ag9?C*
for(int i=0;i<nStartPos.length;i++) d%_OT0Ei
{ DY\J[l<<
if(!fileSplitterFetch.bDownOver) NI aFI(
{ M5g\s;y;
breakWhile = false; T 2F6)e
break; =>iA gp'#
} Qkcjr]#^$
} j$Ab>}g]
if(breakWhile) j8Cho5C
break; !cSq+eD
HCWNo
oD9^ID+
//count++; =LkR!R=
//if(count>4) l+*&:Q/
// siteStop(); U75Jp%bL
} I%j_"r9-I
v&a4^s
gw36Ec<M
System.err.println("文件下载结束！"); ;G\8jP'
} X]%itA
catch(Exception e){e.printStackTrace ();} 8NBT|N~N
} (wRgus
c(#;_Ve2P
-I.d}[
//获得文件长度 UCWV2Mu
public long getFileSize() _>+8og/%@
{ zcrY>t#l
int nFileLength = -1; Dre2J<QL
try{ ",6M)3{|c
URL url = new URL(siteInfoBean.getSSiteURL()); -m *Sq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t>=fTkB
httpConnection.setRequestProperty("User-Agent","NetFox"); NIdZ
%D$]VSP;
%yBB?cp+_
int responseCode=httpConnection.getResponseCode(); s\!>"J bAQ
if(responseCode>=400) 2c6g>?
{ 86]p#n_>Fv
processErrorCode(responseCode); KlRr8G!Z
return -2; //-2 represent access is error *(C(tPhC
} ~t9tnLc$
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fU=B4V4@
String sHeader; .7K7h^*F
'AN>`\mR$
1-lu\"H`
for(int i=1;;i++) cufH?Xg<
{ ,]bB9tid
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F~h7{@\
//Utility.log(in.readLine()); '%q$`KDb
sHeader=httpConnection.getHeaderFieldKey(i); AGLscf.
if(sHeader!=null) 9$2/MT't
{ 'yMF~r3J
if(sHeader.equals("Content-Length")) /p8dZ+X
{ 0$,SF3K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0u\GO;
break; uEX!xx?Q#
} .l.a(_R
} ]]zPq<b2
else FCnm1x#
break; "'D=,*
} /`mks1:pK
} :Nz9xD$S5
catch(IOException e){e.printStackTrace ();} 6I%5Q4Ll
catch(Exception e){e.printStackTrace ();} l<A|d{"]
uD^cxD
[eC2"&}
Utility.log(nFileLength); )ubiB^g'm
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return nFileLength; 8uWa=C)
} 3.*8)NW
p>4-s, W
NuQdSj_>
//保存下载信息（文件指针位置） "g1)f"pL
private void write_nPos() ~^1{B\I
{ d~i+ I5
try{ JU)dr4S?
output = new DataOutputStream(new FileOutputStream(tmpFile)); S[J}UpV
output.writeInt(nStartPos.length); <$IM8Y5p+w
for(int i=0;i<nStartPos.length;i++) NA~Vg8
{ c}2jmwq
// output.writeLong(nPos); AJF#Aw `o
output.writeLong(fileSplitterFetch.nStartPos); ui/a|Q
output.writeLong(fileSplitterFetch.nEndPos); =`H@%
} gcl5jB5)>
output.close(); 1pgU}sRk
} Xg;}R:g '
catch(IOException e){e.printStackTrace ();} .nx2";oi
catch(Exception e){e.printStackTrace ();} woK&q7Vn
} DK:o]~n
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+[\FD; >
//读取保存的下载信息（文件指针位置） mc? Vq
private void read_nPos() J;8IY=
{ @~"h62=] -
try{ $#9;)8J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5>D>% iaHv
int nCount = input.readInt(); :&V h?
nStartPos = new long[nCount]; l)1r+@)\
nEndPos = new long[nCount]; U@uGNMKR
for(int i=0;i<nStartPos.length;i++) jtW!"TOY
{ CVL3VT1j0
nStartPos = input.readLong(); 3u*4o=4e
nEndPos = input.readLong(); L.*M&Ry
} 3KlbP
input.close(); K8GP@yD]M
} 1mOh{:1u
catch(IOException e){e.printStackTrace ();} Vt:~q{9*k
catch(Exception e){e.printStackTrace ();} YIQ 4t
} aBNc(?ri
\`~Ly-
3Q.#c,`jV
private void processErrorCode(int nErrorCode) '7hu 2i5
{ P}n_IV*@
System.err.println("Error Code : " + nErrorCode); DgId_\Ze
} Z>:NPZODf
qr"3y
5q3JI
//停止文件下载 =.Pw`.
public void siteStop() . qO@Q=
{ Z'`<5A%;
bStop = true; GfoLae
for(int i=0;i<nStartPos.length;i++) !Xf5e*1IS
fileSplitterFetch.splitterStop(); 4&<oFW\r
.o(fe\KHf
Dp,L/1GQ8
} ?+@n3]`0
} |W,& Hl7
//负责部分文件的抓取 4;e5H_}Oo
**FileSplitterFetch.java sJL&:!}V>
*/ 4tRYw0f47
package NetFox; `i3NG1 v0
+~m46eI
I8hz(2jI
import java.io.*; S 6@u@C
import java.net.*; }7|1
T*Y~\~Jhu
cLpYW7vZ[
public class FileSplitterFetch extends Thread { W <9T0sZ
9UdM`v)(
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String sURL; //File URL k9sh @ENy
long nStartPos; //File Snippet Start Position w1EXh
long nEndPos; //File Snippet End Position T"{>t
int nThreadID; //Thread's ID ugdQAg
boolean bDownOver = false; //Downing is over M8kPj8}{
boolean bStop = false; //Stop identical 2e+UM$
FileAccessI fileAccessI = null; //File Access interface pnl{&<$C%C
9vuyv*-}e
*'Sd/%8{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l: HTk4$0
{ s1A.+
this.sURL = sURL; ~Z\8UsVN
this.nStartPos = nStart; DrKP%BnS
this.nEndPos = nEnd; bkOv2tZ
nThreadID = id; :%lTU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I&D5;8
} ~8'sBT
}*M6x;t
,Xu-@br{
public void run() "Gsc;X'id
{ Z;ht
while(nStartPos < nEndPos && !bStop) $SlIr<'*"
{ H4WP~(__
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tqz3zIQ
try{ k :(SCHf
URL url = new URL(sURL); b.2aHu( 3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G?L HmTHg
httpConnection.setRequestProperty("User-Agent","NetFox"); lp.ldajN
String sProperty = "bytes="+nStartPos+"-"; @x*c1%wg
httpConnection.setRequestProperty("RANGE",sProperty); kYzIp
Utility.log(sProperty); vLv@&lMW
!y\'EW3|G
\T4v|Pw\
InputStream input = httpConnection.getInputStream(); W>${zVu
//logResponseHead(httpConnection); 52@C9Q,
8H%;WU9-
wg9t)1k{e
byte[] b = new byte[1024]; 1h^:[[!c
int nRead; iowTLq!?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xs{3pkTYD
{ ;;!yC
nStartPos += fileAccessI.write(b,0,nRead); 3U<cWl@
//if(nThreadID == 1) QVv#fy1"6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j_qbAP
} bZ dNibN
GoJ.&aH $
sfpZc7
Utility.log("Thread " + nThreadID + " is over!"); mUNn%E:7@{
bDownOver = true; +jAGGv^)
//nPos = fileAccessI.write (b,0,nRead); MU($|hwiL
} :">!r.Q
catch(Exception e){e.printStackTrace ();} 6Pz4\uE=
} piJu+tUy
} RFi S@.7
?qmRbDI
<ykU6=
//打印回应的头信息 qSM|hHDo)
public void logResponseHead(HttpURLConnection con) R
{ 5GI,o|[s6
for(int i=1;;i++) iJ ($YvF4
{ 9)h"-H;5:
String header=con.getHeaderFieldKey(i); WltQ63u
if(header!=null) uFX#`^r`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &pP;Neh;
Utility.log(header+" : "+con.getHeaderField(header)); "SNn^p59k
else 8Q.T g.
break; /74QMx?
} rF3wx.
} u0}vWkn\4
]MqMQLG0t
]V[q(-Jk
public void splitterStop() M=8.Bp|Ye
{ 5us:adm[pD
bStop = true; 2+RUTOv/d
} Y@NNrGDkT*
2% MC Yn
[xK3F+
} MOQ6:
U2ohHJ``
UBv,=v
/* Yc`o5Q\>
**FileAccess.java aFl;BhM
*//文件访问(定位，写) T tfo^ksw
package NetFox; HNb/-e ,"
import java.io.*; UZWioxsKr+
5A,K6f@:g
{IjF+@I
public class FileAccessI implements Serializable{ hE &xE;
=R^%(Py
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R &nPj~
RandomAccessFile oSavedFile; 3Lfqdqj
long nPos; rExnxQ<e
l.(v^3:X
\9.bt:k@OT
public FileAccessI() throws IOException a`wc\T^
{ C/_ZUF(V
this("",0); 2d>z1%'
} zp6C3RG(
ay4 %
.L+6 $8m
public FileAccessI(String sName,long nPos) throws IOException {WJm
{ 0}<|7?
oSavedFile = new RandomAccessFile(sName,"rw"); y3vdUauOn
this.nPos = nPos; #`~C)=-
oSavedFile.seek(nPos); x!hh"x
} Dxtp2wu%t
oph}5Krd)
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public synchronized int write(byte[] b,int nStart,int nLen) at@G/?
{ X enE^e+9
int n = -1; *=) cQeJ
try{ t1]K<>g
oSavedFile.write(b,nStart,nLen); i)\L:qF5
n = nLen; "RedK '7g
} YP 6`L
catch(IOException e) 6=kEyJT'
{ 6d:zb;Iz
e.printStackTrace (); S2E8Gq9
} rDl*d`He!
"<6G6?sz
S&e0u%8mc
return n; .nTwPrG
} lVd^ ^T*fh
T=<@]$?
@efh{
} =pr`'
# q~e^A b
Y$o<6[7
/* #akpXdXs
**SiteInfoBean.java zofa-7'Bn
*/ w2Us!<x
package NetFox; 90Pl$#cb2
16w|O|^<
m&xW6!x
public class SiteInfoBean { GC<l#3+
&\#sI9
,NOsFO-`<
private String sSiteURL; //Site's URL I?]ohG K
private String sFilePath; //Saved File's Path B3:ez jj
private String sFileName; //Saved File's Name q6@Lp^f
private int nSplitter; //Count of Splited Downloading File e%@'5k\SK
*RDn0d[
tG:25T0
public SiteInfoBean() kh!FR u h
{//nSplitter的缺省值为5 {mm)ay|M
//default value of nSplitter is 5 kd>hhiz|
this("","","",5); !6n_}I-W
} >l]Xz*HE
5rwu!Y;7*
Ua<5U5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6q*9[<8
{ t;\kR4P
sSiteURL= sURL; ) dn(G@5
sFilePath = sPath; cT<1V!L4
sFileName = sName; +:8fC$vVfC
this.nSplitter = nSpiltter; H0:E(}@
O&vVv _zh
bT\1>
} * ;-*x6
J{'>uD.@
^.1)};i
public String getSSiteURL() 4^:\0UF
{ #G.ulX
return sSiteURL; .Fs7z7?Y
} mi ik%7>W
?Fi=P#
e63uLWDT
public void setSSiteURL(String value) O|\J}rm'
{ ! _f9NK
sSiteURL = value; E4xj?m^(y=
} M2d$4-<
=V-A@_^!c
%Da8{%{`Pc
public String getSFilePath() 34z"Pm
{ R,gR;Aarw
return sFilePath; |h-QP#]/
} 4P'*umJi
H+1-]'g`
ZU85P0
public void setSFilePath(String value) jB`,u|FG
{ D'7SAFOM
sFilePath = value; ?sab*$wG
} X59:C3c
'L 8n-TyL
pczug-nB
public String getSFileName() V`X2>-Ex
{ 1|RANy
return sFileName; <PapskO>
} /~}}"zx&
[ad@*KFxy3
*vflscgt
public void setSFileName(String value) cJN7bA{
{ W=vG$
sFileName = value; 1>*#%R?W
} :e]a$
F5?m6`g?
5V6G=H
public int getNSplitter() aEM%R<e
{ !+1<E*NQ S
return nSplitter; W{%TlN
} KB%"bqB|
H18Tn!RDS
d`P7}*;`
public void setNSplitter(int nCount) }lh I\q
{ 0*rQ3Z
nSplitter = nCount; |o{:ZmzM
} [K9'<Qnu
} 2Or'c`|
'ixwD^x
vI2^tX9
/* x$IX5:E#e
**Utility.java %1H[Wh(U
*/ q<\,
package NetFox; 2@9Tfm(=
#bMuvaP~
/4c\K-Z;
public class Utility { L!rw[x
p89wNSMl[
{U!8|(
public Utility() 8S%52W|
{ [21=5S
kB/D!1 "
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} eln&]d;
0(mkeIzJt/
//线程睡眠 ZkAU17f
public static void sleep(int nSecond) jgbLN/_{
{ odPL{XFj
try{ o>/YAX:.!T
Thread.sleep(nSecond); aemc2b*
} c%&:6QniZ
catch(Exception e) : y5<go8e
{ zY,r9<I8_x
e.printStackTrace (); T(e!_VY|m
} rypTKT|U;
} >)spqu]
|_`E1Y}}
//日志 Eve.QAl|
public static void log(String sMsg) O>^C4c!
{ r9 ui|>U"
System.err.println(sMsg); 3jlh}t>$l
} Fb7#<h
t: #6sF
HuwU0:*
public static void log(int sMsg) 6 G3\=)
{ 0TGLM#{
System.err.println(sMsg); |P -8HlOr
} %,D<O,N
} A-4h
/C>wd
q~3,yyu
/* EmODBTu+
**TestMethod.java +m8!U=Zi
*/ vgUb{D
package NetFox; =,Dqqf
,`gl&iB
<^zHE=h"
public class TestMethod { P?t"jKp'
f. FYR|%tq
hir4ZO%Zt
public TestMethod() &|!7Z4N
{ ///xx/weblogic60b2_win.exe SQqD:{#g"
try{ 3'^k$;^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6(G?MW.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _cc#Qlw 7
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q5FM8Q
fileFetch.start(); R,|d`)T
} xfb]b2
catch(Exception e){e.printStackTrace ();} x\J#]d.
#Sa27$&.>
,:??P1
} 2n `S5(V
VY)9|JJCO
h=(DX5:A
public static void main(String[] args) IdXZoY
{ nzmDA6d
new TestMethod(); xia|+
} t`+'r}=d
} * 1Od-3
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