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)); C@!bd+'
} m*vz
for(int i=0;i<nEndPos.length-1;i++) ?$.x%G+
{ cf%aOHYI*
nEndPos = nStartPos[i+1]; E'^ny4gL
} 8u7QF4 Id
nEndPos[nEndPos.length-1] = nFileLength; ?\_vqW
} Wn&9R j
} <z8z\4Hz
: $N43_Wb
mNKcaM?h
//启动子线程 aEn*vun
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6f)7*j~
for(int i=0;i<nStartPos.length;i++) vQ8$C 3
{ j<A<\K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gUH|?@f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }fL ]}&
nStartPos,nEndPos,i); H^<?h6T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y}e3:\
fileSplitterFetch.start(); dpcU`$kt
} \d-9Ndp nf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *Rgl(Ba
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /Nns3oE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %e+{wU}w?2
nEndPos = " + nFileLength); E&>;a!0b]
// fileSplitterFetch[nPos.length-1].start(); 9F7}1cH7g@
XwDt8TxL
8@r>`c
//等待子线程结束 !im%t9
//int count = 0; wU-Cb<^
//是否结束while循环 zICAV -&
boolean breakWhile = false; DaqlL
6W9lKD_i
/$^SiE+N
while(!bStop) {v*X}`.h
{ H/l,;/q]b
write_nPos(); lcXo>
Utility.sleep(500); `l
breakWhile = true; F&HvSt}l5
_mTNK^gB
`2`h4[^ [X
for(int i=0;i<nStartPos.length;i++) # blh9.V&F
{ pV*d"~T
if(!fileSplitterFetch.bDownOver) @ 1FWBH~
{ jQ['f\R
breakWhile = false; [nLd>2P
break; `KUL4) g~
} g ,yB^^%
} GW2v&Ul7(
if(breakWhile) K~+x@O*
break; jvhD_L/
Tsocc5gWZ*
h9QQ8}g
//count++; 7%W@Hr,%F
//if(count>4) h<i.Z7F;tj
// siteStop(); 5hfx2O)
} oI"gQFGu`u
GQ}Rxu]
j]m|}n
System.err.println("文件下载结束！"); XsX];I{E,
} 'y7<!uo?
catch(Exception e){e.printStackTrace ();} ^_/gM[H.
} YGhHIziI
x$KQ*P~q
L#fSP
//获得文件长度 J]|S0JC`
public long getFileSize() 3iw.yR
{ g_)i)V
int nFileLength = -1; F6"QsFG
try{ gF\ac%9
URL url = new URL(siteInfoBean.getSSiteURL()); 9#a/at]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $x2G/5?
httpConnection.setRequestProperty("User-Agent","NetFox"); mxICQ>s b
1-PFM-
W=4|ahk$
int responseCode=httpConnection.getResponseCode(); Lbu,VX
if(responseCode>=400) Vk%W4P"l
{ j#${L6
processErrorCode(responseCode); H%;pPkIi
return -2; //-2 represent access is error Tj=@5lj0
} PMe3Or@
=cxG4R1x
Vu,:rPqI
String sHeader; :AyZe7:(D
Z|j\_VKhl
:fQN_*B4@4
for(int i=1;;i++) 2>.>q9J(
{ l#a*w
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Pz-=Eq
//Utility.log(in.readLine()); ,&jjpeZP
sHeader=httpConnection.getHeaderFieldKey(i); BG+X8t8\
if(sHeader!=null) '8b=4mrbH
{ _#w5hXcu
if(sHeader.equals("Content-Length")) a]4|XJ_
{ Q`UgtL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Nrc-@ ]
break; >Vb V<ak
} ihIRB9
} \{1Vjo
else A&_v:z4y/
break; 9\i^.2&
} 9 'IDbe{
} H}lbF0`
catch(IOException e){e.printStackTrace ();} aq8mD^j-&
catch(Exception e){e.printStackTrace ();} cd$,,
+Q!Kj7EU/
(ewcj\l4*
Utility.log(nFileLength); aWb5w
/_r{7Gq.
>k(AQW5?
return nFileLength; y|YhDO
} =GLMdhD]
%j?7O00@
>c.HH}O0W
//保存下载信息（文件指针位置） 6H:EBj54?
private void write_nPos() {=_xze)
{ YrTjHIn~w
try{ 2hTH
output = new DataOutputStream(new FileOutputStream(tmpFile)); I#|ib
output.writeInt(nStartPos.length); PAu/iqCH
for(int i=0;i<nStartPos.length;i++) QM'>)!8
{ 1 w9Aoc
// output.writeLong(nPos); g'V,K\TG
output.writeLong(fileSplitterFetch.nStartPos); EZ^M?awB4
output.writeLong(fileSplitterFetch.nEndPos); 4'XCO+i#
} h3;RVtS
output.close(); Wl3fR[@3Q
} ;T WYO
catch(IOException e){e.printStackTrace ();} 1JN/oq;
catch(Exception e){e.printStackTrace ();} %xt\|Lt
} #K/#-S
rE\.[mFI
hj[sxC>z5
//读取保存的下载信息（文件指针位置） {1W,-%
private void read_nPos() qFjnuQ,w
{ 92L{be;SY
try{ [Kd"M[1[<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Zy >W2(<
int nCount = input.readInt(); a4N8zDS
nStartPos = new long[nCount]; n:YA4t7S
nEndPos = new long[nCount]; DJHE6XJ
for(int i=0;i<nStartPos.length;i++) &r V
{ '8fL)Zk
nStartPos = input.readLong(); D]d2opBLj
nEndPos = input.readLong(); SZD@<3Nb
} mOx>p"n
input.close(); ~ *P9_<
} U6oab9C?k
catch(IOException e){e.printStackTrace ();} }ABHGr5[
catch(Exception e){e.printStackTrace ();} xiQ;lE
} tNCKL.yU
,U'E!?=:VS
x<{)xP+|
private void processErrorCode(int nErrorCode) %:[Y/K-
{ w~VqdB
System.err.println("Error Code : " + nErrorCode); }L|XZL_Jo#
} S|ADu]H(
(+0yZ7AZ
Z6oA>D
//停止文件下载 0G/_"}@
public void siteStop() z@J;sz
{ lF!Iu.MM 9
bStop = true; -44''w?z
for(int i=0;i<nStartPos.length;i++) !u|s|6{\
fileSplitterFetch.splitterStop(); AN-;*n<'
@KC;"u'C
#[Vk#BIiv8
} pJ]i)$M
} 3UQ~U 8
//负责部分文件的抓取 (Y]G6> Oa
**FileSplitterFetch.java PQ[x A*
*/ w\ 7aAf3O
package NetFox; )NS&1$
=k22f`8ew
nD;8)VI'I
import java.io.*; yn-TN_/Y,
import java.net.*; \~'+TW
P[C03a!lXg
a]_eSU@
public class FileSplitterFetch extends Thread { VcR(9~
M]OZS\9.B
*1 l"|=_&s
String sURL; //File URL %q 7gl;'
long nStartPos; //File Snippet Start Position n+uDg
long nEndPos; //File Snippet End Position h^"OC$
int nThreadID; //Thread's ID I%31MU9
boolean bDownOver = false; //Downing is over pwO U6A!
boolean bStop = false; //Stop identical j#E&u*IR
FileAccessI fileAccessI = null; //File Access interface dzZ75
%1VfTr5
:i:M7}r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IEW[VU)
{ ?AJE*=b
this.sURL = sURL; 0^rDf L
this.nStartPos = nStart; *^P$^lm?S
this.nEndPos = nEnd; t.WWahNyY
nThreadID = id; w"K;e(S
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6H}8^'/u
} Qape DU;
U49 `!~b7
+cnBEv~y
public void run() RP4P"m(
{ lGtTZcg
while(nStartPos < nEndPos && !bStop) " )_-L8
{ Vtr5<:eEx
S^4T#/
)YP9
try{ "kT?9&
URL url = new URL(sURL); " tUF,G(<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IF$*6 ,v.z
httpConnection.setRequestProperty("User-Agent","NetFox"); <:UP
String sProperty = "bytes="+nStartPos+"-"; *(sFr E
httpConnection.setRequestProperty("RANGE",sProperty); w*"h#^1z
Utility.log(sProperty); E<XrXxS1O
g}=opw6z
@fxDe[J:
InputStream input = httpConnection.getInputStream(); \zPcnDB
//logResponseHead(httpConnection); G;3N"az
1#<KZN =$
Z,jK(7D(
byte[] b = new byte[1024]; c*#*8R9.y
int nRead; @d86l.=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }hv" ku6!
{ '+cPx\4
nStartPos += fileAccessI.write(b,0,nRead); THbV],RhJ
//if(nThreadID == 1) #$[}JiuL/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5?n@.hcL
} jVtRn.qh
m'i^BE
R59'KR2?
Utility.log("Thread " + nThreadID + " is over!"); k3wAbGp
bDownOver = true; v}AVIdR
//nPos = fileAccessI.write (b,0,nRead); +sc--e?
} wO {-qrN
catch(Exception e){e.printStackTrace ();} &p2fMVWJ7
} `upxM0gc
} <..|:0Q&~
1v^eXvY
\E<t'\>@X
//打印回应的头信息 [10;Mg
public void logResponseHead(HttpURLConnection con) UI>?"b6 L
{ 1]<wZV}.
for(int i=1;;i++) `vFYeN;
{ gP?uLnzvi
String header=con.getHeaderFieldKey(i); )W& $FU4JK
if(header!=null) `Mp-4)mn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %IbG@}54
Utility.log(header+" : "+con.getHeaderField(header)); p/k6}Wl
else rpu{YC1C%
break; i>`!W|=_
} psZAO,p
} .\X;VWTI
It/IDPx4ga
T1Q c?5K^
public void splitterStop() Tn7(A^h'
{ UoiXIf_Q
bStop = true; 8#MiM . f
} 3M[b)At V.
a!US:^}lu
h^}r$k_n
} _#8OHG.x
ZCbnDj
Y@Zv52,
/* &gL &@';,
**FileAccess.java 8T#tB,<fFW
*//文件访问(定位，写) \%FEQa0u
package NetFox; -}Iw!p#O3
import java.io.*; J!GWP:b3
1/H9(2{L
k7gm)}RKcu
public class FileAccessI implements Serializable{ DJmT]Q]o)
0cwb^ffN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e5 ?;{H
RandomAccessFile oSavedFile; TEK]$%2
long nPos; eaxp(VX?oy
/M1 /
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public FileAccessI() throws IOException u`]J]gE
{ 7O,y%NWaK
this("",0); }RvP*i
} oe8sixZ[
L/VlmN_v>s
$C;)Tlh
public FileAccessI(String sName,long nPos) throws IOException dSkW[r9Z%l
{ E?z~)0z2`
oSavedFile = new RandomAccessFile(sName,"rw"); ^atX/
this.nPos = nPos; h8Bs=T
oSavedFile.seek(nPos); !A\Qwg>
} \MA4>
d/k70Ybk
dt -=7mz#
public synchronized int write(byte[] b,int nStart,int nLen) JAK+v
{ f2JeXsOI
int n = -1; &ZRriqsQg
try{ H.HXwN/x
oSavedFile.write(b,nStart,nLen); i@C1}o-/
n = nLen; Oz[]]`C1
} 1$*ZN4
catch(IOException e) =wEqI)Td
{ Vu/{Hr
e.printStackTrace (); C#r1zr6
} Y|NANjEAfm
s 9Y'MQo*
;e>pu"#
return n; o-))R| ~z
} 8pQx6QE
\C )S3!h
?4kM5NtP
} t@`w}o[#
ky`xBO=
DaV:Slp9
/* W]]@pbG"H\
**SiteInfoBean.java NEpomE(>x
*/ BJ0P1vh6M
package NetFox; }'y=JV>l
q;^Q1[Ari
pE<@
public class SiteInfoBean { g8JO/s5xV
<@DF0x!
O]>FNsh!
private String sSiteURL; //Site's URL LovVJ^TD0i
private String sFilePath; //Saved File's Path ^Lx(if WJ
private String sFileName; //Saved File's Name _NfdJ=[Xh
private int nSplitter; //Count of Splited Downloading File \lJCBb+k
w&vZ$n-|
mM> L0
public SiteInfoBean() [p+]H?(A
{//nSplitter的缺省值为5 [IF5Iv\b
//default value of nSplitter is 5 Pp*:rA"N
this("","","",5); < )dqv0=
} J-6l<%962%
3N(5V;ti
X7cqAi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <}G*/ z?/
{ 0%Y8M` ~s7
sSiteURL= sURL; fd{75J5%
sFilePath = sPath; =i4%KF9x
sFileName = sName; VO (KQx
this.nSplitter = nSpiltter; A)2eo<ij4
V__|NVoOm
C#^V<:9
} B1x# 7>K
=N62 ){{
9vQI ~rz?
public String getSSiteURL() Y]xFe>
{ Z%Kkh2-uh
return sSiteURL; X 5.%e&`
} \iBEyr]
kBh*@gf
|XDbf3^6
public void setSSiteURL(String value) ?5N7,|K)
{ [MQU~+]
sSiteURL = value; <}\!FuC
} V<:)bG4;d
f,jN"
\jkMnS6FvL
public String getSFilePath() ?06+"Z
{ SBf8Ipe
return sFilePath; :i?7RouO
} x1@`\r#0
u8w4e!rKo6
`X["Bgk$!T
public void setSFilePath(String value) MO_-7,.y
{ %kHeU=
sFilePath = value; 0eGz|J*7
} wM-I*<L>
5~,/VV
DOsQVdH
public String getSFileName() ?~%Go
{ agbG)t0
return sFileName; aUGRFK_6$
} E*sQ|" g
TrYt(F{t
0r=KY@D
public void setSFileName(String value) 'lsG?
{ !OCb^y
sFileName = value; \CY_nn|&g
} kH.W17D~
Vr<eU>W
U.$7=Zl8t
public int getNSplitter() m0}1P]dc
{ 8]`LRzM
return nSplitter; ?2q;`Nb
} PnUYL.v
}akF=/M
aqw;T\GI+~
public void setNSplitter(int nCount) )S8fFV
{ l_ES$%d
nSplitter = nCount; 1ti9FQ
} e5GJ:2sH
} <o aVI?
Vx~N`|yY
#:)yh]MP
/* V-7A80!5
**Utility.java RBA{!
*/ CJ~gE"
package NetFox; URo#0fV4C
Xi:y35q
,rU>)X
public class Utility { ;X zfd
U2DE zr
,S%DHT
public Utility() vNA~EV02
{ =SUCcdy&
a(s%3"*Q
U WU PY
} 3G.-JLhs
s|O4>LsG
//线程睡眠 <5xlP:Cx
public static void sleep(int nSecond) O-N@HZC
{ PCcI(b>?l
try{ Lj,!025
Thread.sleep(nSecond); |4_[wX r
} h{Zd, 9H
catch(Exception e) gK6_vS4K)
{ 9i?Q=Vuc~<
e.printStackTrace (); U9/>}Ni%3G
} H wu(}
} 79bt%P
/7o{%~O
//日志 9R1S20O
public static void log(String sMsg) u&npUw^Va
{ p(8[n^~,i
System.err.println(sMsg); "%?$BoJR0
} { ML)F]]
}u `~lw(Z
;+Mee^E>!
public static void log(int sMsg) XZew$Om[
{ *;0Ods+IcY
System.err.println(sMsg); ,QZNH?Cp/
} xV+cX*4h
} qQ/<\6Sl
*@-a{T}
AnD#k]
/* VS\+"TPuH
**TestMethod.java l.Yq4qW
*/ C"[d bh!
package NetFox; ]T<\d-!CZN
t91z<Y|
rF:l+I]
public class TestMethod { "P9SW?',
$psPNJG
[Q:C\f]
public TestMethod() }%lk$g';
{ ///xx/weblogic60b2_win.exe ~1g)4g~
try{ j}F;Bfq!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4^uwZ:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l2ww3)Z
SiteFileFetch fileFetch = new SiteFileFetch(bean); G{!adBna
fileFetch.start(); #BOLq`9f
} rWS],q=c
catch(Exception e){e.printStackTrace ();} }48o{\
])vWvNx
4Mr)~f rc
} 0\tdxi
TMAart;<
3zsjL=ta
public static void main(String[] args) 032PR;]
{ A` )A=L
new TestMethod(); eZ`x[g%1
} $:!L38[7$
} 0WO-+eRB/
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