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 {gYrz)
} nQb{/ TqC'
for(int i=0;i<nEndPos.length-1;i++) bv-s}UP0
{ OlQ7Yi>
nEndPos = nStartPos[i+1]; D<C ZhYJ
} Dtt[a
nEndPos[nEndPos.length-1] = nFileLength; E*i <P
} px".pYr0
} "=N[g
-"#;U`.oh7
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//启动子线程 _T)dmhG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; r^q@rL>
for(int i=0;i<nStartPos.length;i++) !ku5P+y$
{ h1q?kA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L1 O\PEeT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Tz:mj
nStartPos,nEndPos,i); grp1nWAs
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "~> # ;x{
fileSplitterFetch.start(); $x)C_WZj?
} DgGGrV`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), VMe~aUd
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wspZ Eu>C;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LSs!U 3"
nEndPos = " + nFileLength); LhUrVydL
// fileSplitterFetch[nPos.length-1].start(); !:'%'@uc
\,+act"v
=TE6R 0b
//等待子线程结束 y_;LTCj?
//int count = 0; CuR.a
//是否结束while循环 MR}GxI
boolean breakWhile = false; 0sD"Hu
8*k#T\
cNZuwS~,
while(!bStop) 0B7cpw>_J
{ ]k-<[Z;I,
write_nPos(); 7Y"CeU-S
Utility.sleep(500); $DuX1T
breakWhile = true; ZaIlo5
7^>UUdk(
[7]Kvb2t
for(int i=0;i<nStartPos.length;i++) ^rO3B?_
{ @doo2qqIe]
if(!fileSplitterFetch.bDownOver) .'.#bH9K
{ N|WZk2 "
breakWhile = false; ;nW#Dn9
break; t2Q40' `
} $d? N("L
} _BHR ?I[w
if(breakWhile) e@}zp
break; EdbLAagI6
w 4-E@>%
>1 {V
//count++; ,1J+3ugp&
//if(count>4) KV v0bE
// siteStop(); Z#0hh%E"|y
} U>PF#@ C/
mF7T=pl
kqxX!
System.err.println("文件下载结束！"); *8ykE
} l?F-w;wHN
catch(Exception e){e.printStackTrace ();} ky*-THS
} O%?noW
}A)>sQ
\i%h/Ao
//获得文件长度 `3GC}u>}
public long getFileSize() 'Pyeb`AXE9
{ unn2MP'
int nFileLength = -1; DWT4D)C,U
try{ ANgfG8>
URL url = new URL(siteInfoBean.getSSiteURL()); H=Sy.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $!F_K
httpConnection.setRequestProperty("User-Agent","NetFox"); doM}vh)6
N]qX^RSb
iX ;E"ov]
int responseCode=httpConnection.getResponseCode(); U6SgV 8
if(responseCode>=400) Q(Uj5aX
{ an!ceB
processErrorCode(responseCode); V-rzn171Q)
return -2; //-2 represent access is error ^@V$'Bk
} p<hV7x-{
^3`CP4DT
'Y`.0T[&
String sHeader; /Hxz@=LC1
57:Wh=x
oB$7m4xO\
for(int i=1;;i++) .CXe*Vbd
{ CYlZ<W'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |%6zhkoufM
//Utility.log(in.readLine()); \VJ7ahg[\
sHeader=httpConnection.getHeaderFieldKey(i); nFE0y3GD8
if(sHeader!=null) }M%U}k]+@
{ <3]Qrjl ,b
if(sHeader.equals("Content-Length")) 9D 2B8t"a
{ WR;"^<i9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); u[25U;xo
break; I^'U_"vB
} t%jB[w&,os
} 3'(w6V
else tF> ?]
break; gm;6v30e
} G4Y]fzC
} xv! QO
catch(IOException e){e.printStackTrace ();} "+^d.13+]
catch(Exception e){e.printStackTrace ();} y7 tK>aD}
;1`NsYI2
v&CKtk!3{
Utility.log(nFileLength); |BysSJ
(C;oot,
neC]\B[Xm
return nFileLength; v&:R{
} T""y)%
<{\UE~
@C),-TM
//保存下载信息（文件指针位置） =\IcUY,4
private void write_nPos() v5i?4?-Z
{ =A,32&;@N
try{ 7 R1;'/;
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?&Y3Fr)%
output.writeInt(nStartPos.length); sePOW#|
for(int i=0;i<nStartPos.length;i++) w+vYD2a
{ w}Q|*!?_
// output.writeLong(nPos); .^s%Nh2jM
output.writeLong(fileSplitterFetch.nStartPos); 4i'2~w{/
output.writeLong(fileSplitterFetch.nEndPos); 7. y L>
} Q}!U4!{i|p
output.close(); h~$Q\WCm#
} %v++AcE
catch(IOException e){e.printStackTrace ();} 5utMZ>%w_#
catch(Exception e){e.printStackTrace ();} Mnpb".VU#T
} >iP>v`J
5gq3 >qo
wL 5p0Xl
//读取保存的下载信息（文件指针位置） gM|X":j
private void read_nPos() DBi3 j
{ o?P(Fuf
try{ }#@P+T:b
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WU1I>i
int nCount = input.readInt(); whP>'9t.w
nStartPos = new long[nCount]; jr"~
nEndPos = new long[nCount]; ,*.C''
for(int i=0;i<nStartPos.length;i++) >*A\/Da]j
{ ,2?"W8,
nStartPos = input.readLong(); *>.~f<V
nEndPos = input.readLong(); 0-Xpq,0
} /= P!9d {
input.close(); KM(U-<<R
} r2QC$V:0
catch(IOException e){e.printStackTrace ();} zqYfgV
catch(Exception e){e.printStackTrace ();} e*vSGT$KgL
} (JFa
/>\.zuAr&
#UU}lG
private void processErrorCode(int nErrorCode) rjU $*+
{ B!<{s'
System.err.println("Error Code : " + nErrorCode); > ^3xBI:Q
} fE)+9!
h bj^!0m
>T~{_|N
//停止文件下载 5n.4>yOY
public void siteStop() n<yV]i$
{ #eE:hiu<v
bStop = true; r3Z-mJ$:
for(int i=0;i<nStartPos.length;i++) .(;k]UP
fileSplitterFetch.splitterStop(); Cgw#c%
/]]\jj#^
*goi^Xp
} IG +nrTY0
} 2~h)'n7Mw
//负责部分文件的抓取 wSV[nK
**FileSplitterFetch.java n2,b~S\e
*/ C&Nd|c
package NetFox; pfAp2"
Q;r 0#"
{yVi/*;f^
import java.io.*; {LJCY<IGq
import java.net.*; 7-e)V{A`w
aDza"Ln
[Z Ea3/
public class FileSplitterFetch extends Thread { tvRa.3
"cJ5Fd:*
>)N,V;j
String sURL; //File URL 5+%BZ
long nStartPos; //File Snippet Start Position b'9G`Y s^
long nEndPos; //File Snippet End Position 8Yq6I>@!
int nThreadID; //Thread's ID o}WbW }&
boolean bDownOver = false; //Downing is over T_AZCl4d
boolean bStop = false; //Stop identical NX)7g}S
FileAccessI fileAccessI = null; //File Access interface %q>gwq A
b@,=;Y)O
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException D"1ciO8^I]
{ UQW;!8J#R(
this.sURL = sURL; >+oQxml6nI
this.nStartPos = nStart; qd{|"(9B
this.nEndPos = nEnd; u> >t"w
nThreadID = id; PI0/=kS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >b*Pd *f
} Vi#(x9.
H`@x5RjS
>Ckb9A
public void run() M5)6|T
{ uF(-h~
while(nStartPos < nEndPos && !bStop) kFk+TXLDIt
{ KQW
u4+VG5.rhT
u%*;gu"2
try{ ~=c^Oo:
URL url = new URL(sURL); .Uih|h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?+Qbr$]
httpConnection.setRequestProperty("User-Agent","NetFox"); U}Hmzb
String sProperty = "bytes="+nStartPos+"-"; G0*$&G0nb
httpConnection.setRequestProperty("RANGE",sProperty); z5Nw+#m| i
Utility.log(sProperty); 23+GX&Rp
U_I'Nz!^t
^jCkM29eu
InputStream input = httpConnection.getInputStream(); tU)+q?Mw
//logResponseHead(httpConnection); `C!Pe84(
m&ZdtB|
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byte[] b = new byte[1024]; $rjv4e}7
int nRead; 5Vvy:<.la
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VNytK_F0P
{ R6AZIN:
nStartPos += fileAccessI.write(b,0,nRead); ((?^B
//if(nThreadID == 1) Jn:GqO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9CL&tpqv f
} (iS94}-)
aMj3ov8p
mX2Qf8
Utility.log("Thread " + nThreadID + " is over!"); +F0M?,
bDownOver = true; \{~x<<qFd
//nPos = fileAccessI.write (b,0,nRead); 74Kl!A
} +*|E%pq
catch(Exception e){e.printStackTrace ();} 1P[!B[;c
} 8Ipyr%l
} K, 35*
>eU;lru2Q
S:R%%cy
//打印回应的头信息 b1s1;8Q
public void logResponseHead(HttpURLConnection con) h"<rW7z
{ 4Q!*h8O
for(int i=1;;i++) 3[Z?`X
{ OY@/18D<>
String header=con.getHeaderFieldKey(i); WS,p}:yPZG
if(header!=null) Y#rao:I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5SK.R;mn
Utility.log(header+" : "+con.getHeaderField(header)); @h$7C<
else ]p$fEW g
break; 9RAN$\AKy
} >B3_P4pW9
} /h
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`VS/Xyp
public void splitterStop() wtRAq/
{ b ~F85U2
bStop = true; N b+zP[C
} = [:ruE
G`TO[p]q
.Z9Bbab:
} Aw >DZ2
RX#:27:
38JvJR yK}
/* `A?/Ww>;
**FileAccess.java fkYa
*//文件访问(定位，写) QhN5t/Hr
package NetFox; G0<m3 Up
import java.io.*; R{Cj]:Ky
Pc1vf]
:5p`H
public class FileAccessI implements Serializable{ ^gD&NbP8
](3=7!!J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +jQW6k#
RandomAccessFile oSavedFile; 2}hEBw68
long nPos; $S3C_..
@_0XK)pW
J4=~.&6
public FileAccessI() throws IOException 8BBuYY{
{ JrS|Ib)6
this("",0); wR\%tumk
} *<]ulR2
rr9N(AoxW
l2z@t3{
public FileAccessI(String sName,long nPos) throws IOException 1@;Dn'
{ rVkRU5
oSavedFile = new RandomAccessFile(sName,"rw"); ZC@Pfba[`
this.nPos = nPos; `BF+)fs
oSavedFile.seek(nPos); eY;XF.mF
} =`99ez+y
RQ!kVM@
AwUcU;"9>
public synchronized int write(byte[] b,int nStart,int nLen) M;-PrJdyt
{ ={B%qq
int n = -1; SwXVa/9a"
try{ 'de&9\
oSavedFile.write(b,nStart,nLen); RGf&KV/
n = nLen; VMXccT9i!
} O,x[6P54P
catch(IOException e) ot($aY,t
{ 4hz T4!15
e.printStackTrace (); e ^2n58
} +0_e a~{
m%]1~b}"
i}[cq_wJ
return n; Y 3h`uLQ
} ose(#n40
:m]H?vq] \
N:x--,2
} JuQwZ]3ed
N?`V;`[
{bHUZen
/* ' Dcj\=8
**SiteInfoBean.java >~:Md
*/ EMQGP<[
package NetFox; cD6S;PSg
p>_Qns7W
=gNPS0H
public class SiteInfoBean { %|j`z?i|
s|IY t^
J?{@pA
private String sSiteURL; //Site's URL aKjP{Z0k$
private String sFilePath; //Saved File's Path Co>e<be%S
private String sFileName; //Saved File's Name 76H>ST@G|
private int nSplitter; //Count of Splited Downloading File `6$|d,m5
d|?Xo\+
JTIt!E}P
public SiteInfoBean() 0FSNIPx
{//nSplitter的缺省值为5 E75/EQ5p]p
//default value of nSplitter is 5 *4/FN TC
this("","","",5); 'X<4";$mU
} :of(wZa3Q
n{u\t+f
mG"xo^1_H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &1(- 8z*
{ ,qx^D
sSiteURL= sURL; b7XB l
sFilePath = sPath; Kv<f<>|L
sFileName = sName; Kci. ,I
this.nSplitter = nSpiltter; wA\5-C7j
@-}*cQ4u?
0j_kK
} h5SJVa
nl qn:[BU
=:aJZ[UU<2
public String getSSiteURL() f(Y_<%
{ !$A/.;0$
return sSiteURL; 2]1u0-M5L
} Jy5sZ}t[
As<B8e]
O&1qL)
public void setSSiteURL(String value) T]\c2U
{ ];Z6=9n
sSiteURL = value; tLBtE!J$[
} } vmRm*8z
8q@Z
ZUHRATT-
public String getSFilePath() )P$|9<_q7x
{ *!%lBt{2
return sFilePath; n:,mo}?X
} 2%dL96
N ~{N Nf Y
X*QS/\
public void setSFilePath(String value) H5T_i$W
{ LWyr
sFilePath = value; |'q%9#
} 83n%pS4x
M2O_kOeZ
#;$]M4
public String getSFileName() rW:krx9
{ d~Z\%4
return sFileName; u= NLR\
} K]hp-QK<
}d<R 5
"9wD|wsz
public void setSFileName(String value) uh)S;3|
{ `7CK;NeT
sFileName = value; xG9Sk
} cJ;Nh>ey
Rff F:,b
`Mnu<)v
public int getNSplitter() 4J2^zx,H
{ JZ:@iI5>+
return nSplitter; aQCu3T
} 5E&#Kh(I
nlwqSXw
A&Y5z[p
public void setNSplitter(int nCount) EY,jy]|#
{ 9}(w*>_L
nSplitter = nCount; R4m{D
} e-nA>v
} [3Pp NCY
zLpCKndj
o~Se[p
/* Q&} 0owe
**Utility.java ZK5nN9`
*/ M:S-%aQ_<y
package NetFox; l8\UO<^fY
CMa6':~
c-a,__c?hx
public class Utility { M]x>u@JH
b 7UJ
g.lTNQm$u
public Utility() J|`0GDSn
{ h051Ol\v*
C($l'jd&
d1b]+AG4
} ;_o]$hV|
Ql*zl
//线程睡眠 Shm> r@C?
public static void sleep(int nSecond) ;G[V:.o-
{ }E'0vf/
try{ c8l>OS5i3_
Thread.sleep(nSecond); "6B7EH
} .tngN<f
catch(Exception e) ]<;,HGO
{ 8y;Rw#Dz
e.printStackTrace (); }A#IBqf5
} .E4*>@M5
} Vwkvu&4
ARk(\,h
//日志 8nz({Mb9Z
public static void log(String sMsg) dmFn0J-\
{ i"8mrWb
System.err.println(sMsg); ^h(wi`i
} R.~[$G!
h^M_yz-f
l$42MRi/
public static void log(int sMsg) / f%mYL
{ |V9[aa*c
System.err.println(sMsg); _(W@FS
} e8m,q~%#/
} 7_0p& 3
&Y@i:O
U1RU2M]v
/* =L6#=7hcl
**TestMethod.java 5!-TLwl`j\
*/ $( hT{C,K
package NetFox; / 3A6xPOg
$=aO*i
%@$UIO,(
public class TestMethod { tne_]+
RNg?o[S
*$f=`sj
public TestMethod() ys_2?uv
{ ///xx/weblogic60b2_win.exe h Yu6PWK
try{ iD^,O)b
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |Uh8b %
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9 {4yC9Oz>
SiteFileFetch fileFetch = new SiteFileFetch(bean); uuzV,q
fileFetch.start(); m]p{]6h
} |tXA$}"L8
catch(Exception e){e.printStackTrace ();} qi-XNB`b
f/Gx}x=
tgRj8 @
} }gp@0ri%5
9zaNfs
X.]I4O&_
public static void main(String[] args) _e%D/}
{ Q>niJ'7WF
new TestMethod(); xR7ZqTcw
} N?GTfN
} ~.a"jYb7A}
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