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)); *lyy|3z
} sB`.G
for(int i=0;i<nEndPos.length-1;i++) e}>3<Dh
{ !xcLJ5^W
nEndPos = nStartPos[i+1]; Oxsx\f_
} RT`.S uN
nEndPos[nEndPos.length-1] = nFileLength; D=1:-aLP7
} f$1&)1W[
} [wOz<<
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uJ-Q]yQ
//启动子线程 MTXh-9DA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jKr\mb
for(int i=0;i<nStartPos.length;i++) P^[eTR*?
{ pLj[b4p9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *I]/ [d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +2xgMN6B@
nStartPos,nEndPos,i); 9Xl[AVs:M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R*0]*\C z
fileSplitterFetch.start(); 7<GC{/^T
} | KtI:n4d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ui?iMtDr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]QC9y:3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &fofFVQnW
nEndPos = " + nFileLength); W{Uz#o
// fileSplitterFetch[nPos.length-1].start(); Sf*1Z~P|
V#X#rDfJZ
UahsX
//等待子线程结束 ;n,xu0/
//int count = 0; mqj]=Fq*
//是否结束while循环 Mc,3j~i
boolean breakWhile = false; ?_ 476A
ci 4K Nv;
r)S:-wP
while(!bStop) 0:I[;Qt
{ PH.g+u=v
write_nPos(); H^ 'As;R
Utility.sleep(500); or,:5Z
breakWhile = true; FYs]I0}|
8;Zz25*
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for(int i=0;i<nStartPos.length;i++) ~Uw;6VXV1
{ .jUM'; l
if(!fileSplitterFetch.bDownOver) rjK]zD9
{ )E|{.K
breakWhile = false; 9U>OeTh(
break; )Cu2xRr^`
} y%Rq6P=4Q
} Ie4\d2tQ;
if(breakWhile) :W^\ }UX4
break; CY~ S{w
t"JE+G
"7q!u,u
//count++; F[(ocxQZ3
//if(count>4) E)%DLZ
// siteStop(); +pPfvE`
} ee/3=/H|;
`^ZhxFX
Gg e X
System.err.println("文件下载结束！"); 9;7Gzr6A"
} O!!N@Q2g
catch(Exception e){e.printStackTrace ();} av&~A+b.r
} v-Tkp Yn
H-rxn
3{)!T;Wd
//获得文件长度 OUq%d8W
public long getFileSize() Al1_\vx7
{ n:|a;/{I]9
int nFileLength = -1; {p.^E5&
try{ %nRgHN>
URL url = new URL(siteInfoBean.getSSiteURL()); 9>ajhFyOhX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8eVy*h2:=
httpConnection.setRequestProperty("User-Agent","NetFox"); gky+.EP.
_h+7KK
J#W*,%8O
int responseCode=httpConnection.getResponseCode(); WeJ=]7T'L
if(responseCode>=400) +T\<oj%}2
{ ,wf:Fr
processErrorCode(responseCode); G2<$to~{
return -2; //-2 represent access is error 5S<Rz)1r
} #_eXybUV
L{&>,ww
b(oe^jeGz
String sHeader; N5c*#lHI
4a0Ud !Qcs
~&?57Sw*m
for(int i=1;;i++) X J`*dgJ
{ Xdi<V_!BC-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qV9}N-sS
//Utility.log(in.readLine()); NH;e|8
sHeader=httpConnection.getHeaderFieldKey(i); \ZM5J
if(sHeader!=null) A9lw^.
{ eC"k-a8j+
if(sHeader.equals("Content-Length")) |8pSMgN
{ denxcDFu/~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {#st>%i
break; NN#k^[i1
} 4> uNH5
} IQ$!y,VJ
else c2t`i
break; R#3zGWr~
} 3?K+wg s
} 6cd!;Ca
catch(IOException e){e.printStackTrace ();} A!,c@Kv 3
catch(Exception e){e.printStackTrace ();} zMRa<G7
N5{v;~Cm}V
tm/=Oc1p
Utility.log(nFileLength); Tdade+
t>Ye*eR*`U
?N<,;~
return nFileLength; Nyt*mbd5 {
} ~j>yQ%[v
[;yKbw!C
{+zG.1o^
//保存下载信息（文件指针位置） _CPj]m{
private void write_nPos() [O<F`u"a
{ oP`:NCj\9
try{ L pq)TE#
output = new DataOutputStream(new FileOutputStream(tmpFile)); 43E)ltR=]
output.writeInt(nStartPos.length); o{>4PZ}=g
for(int i=0;i<nStartPos.length;i++) X1d{7H8A2
{ 5kGQf
// output.writeLong(nPos); w[F})u]E
output.writeLong(fileSplitterFetch.nStartPos); 8nng^
output.writeLong(fileSplitterFetch.nEndPos); =/}Rnl+c
} !uit
output.close(); JNY?]|=
} tmOy"mq67
catch(IOException e){e.printStackTrace ();} *xJ]e.
catch(Exception e){e.printStackTrace ();} `v@Z|rv,
} X&HYWH'@,
-. o,bg
Fm=jgt3wv8
//读取保存的下载信息（文件指针位置） ia3Q1 9r
private void read_nPos() :1Nc6G
{ etT9}RbQ
try{ \?oT.z5VG&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k;jl3GV
int nCount = input.readInt(); Dt<MEpbur
nStartPos = new long[nCount]; lX%-oRQ/os
nEndPos = new long[nCount]; sVr|kvn2
for(int i=0;i<nStartPos.length;i++) KAXjvZN1
{ c]Gs{V]\
nStartPos = input.readLong(); 2z*}fkJ
nEndPos = input.readLong(); Z'`\N@c#
} <p CD>
input.close(); `*[\b9>
} Y#I8gzv
catch(IOException e){e.printStackTrace ();} yZ{N$ch5b
catch(Exception e){e.printStackTrace ();} p:4-b"O
} ?A;RTM
O:8 u^TP
h<)ceD<,
private void processErrorCode(int nErrorCode) qE3Ud:j
{ rHjDf[5+
System.err.println("Error Code : " + nErrorCode); C[<{>fl)
} 6\u. [2lE^
p+<qI~
p2Gd6v.t
//停止文件下载 V dvj*I
public void siteStop() ]Tb?z&
{ k~so+k&=b
bStop = true; ,tQNL\t
for(int i=0;i<nStartPos.length;i++) Y@:l!4DI
fileSplitterFetch.splitterStop(); _f8H%Kgk;
5=8v\q?)c
t\LE\[XM>
} 50dN~(;p
} IP$eJL[&D"
//负责部分文件的抓取 JBA{i45x
**FileSplitterFetch.java xv Xci W
*/ 8\9W:D@"x
package NetFox; kssRwe%>;
u$[&'D6
{ZSAPq4)L
import java.io.*; bDIhI}P
import java.net.*; zRmVV}b
H;NAS/OhS
wl%ysM|x
public class FileSplitterFetch extends Thread { m' S{P:TK
A W6B[
g33Y$Xdk
String sURL; //File URL ]hy@5Jyh
long nStartPos; //File Snippet Start Position Du +_dr^4
long nEndPos; //File Snippet End Position QHja4/
int nThreadID; //Thread's ID WF*j^ %5
boolean bDownOver = false; //Downing is over xjF>AAM_Px
boolean bStop = false; //Stop identical 8RuW[T?
FileAccessI fileAccessI = null; //File Access interface GOGS"q
X^dasU{*
*~4<CP+"0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~8UMwpl-
{ l%('5oz@\
this.sURL = sURL; {X2uFw Gi
this.nStartPos = nStart; {>vgtkJ
this.nEndPos = nEnd; @aN~97 H\
nThreadID = id; ZvQZD=,F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7Y-Q, ?1
} uH?4d!G
#g@4c3um|
~3Pp}eO~V
public void run() a!4p$pR
{ = 03G~7B>
while(nStartPos < nEndPos && !bStop) cUP1Uolvn
{ O"|d~VQ
Yc?S<
j~S=kYrGM
try{ g"Hl 30o
URL url = new URL(sURL); 3?<A]"X.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1c@S[y
httpConnection.setRequestProperty("User-Agent","NetFox"); h4itXJy52B
String sProperty = "bytes="+nStartPos+"-"; 5(\/ b<#
httpConnection.setRequestProperty("RANGE",sProperty); 7)1%Z{Dy
Utility.log(sProperty); ]b>XN8y.
g18zo~LZ
!gV{[j?~zr
InputStream input = httpConnection.getInputStream(); :-U&_%#w
//logResponseHead(httpConnection); =bP<cC=3b
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oiR9NB&<
byte[] b = new byte[1024]; Z_dL@\#|
int nRead; THX% z `
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vol (%wB
{ },}g](!m
nStartPos += fileAccessI.write(b,0,nRead); t~dK\>L
//if(nThreadID == 1) h+!R)q8M
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wj0_X;L
} hP{+`\&<f
+A1*e+/b\
gBWr)R
Utility.log("Thread " + nThreadID + " is over!"); c;]^aaQ+>
bDownOver = true; >ySO.S
//nPos = fileAccessI.write (b,0,nRead); 7JuHa /Mv
} kREFh4QO,
catch(Exception e){e.printStackTrace ();} \(=xc2
} G\5Bdo1g
} of7p~{3H
A /c
/E{tNd^S
//打印回应的头信息 LkK&<z
public void logResponseHead(HttpURLConnection con) -Vb5d!(
{ D-t!{LA
for(int i=1;;i++) 8 l= EL7
{ yn@wce
String header=con.getHeaderFieldKey(i); @`nG&U
if(header!=null) %dr*dA'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); lTN^c?
Utility.log(header+" : "+con.getHeaderField(header)); m+7%]$
else !B#lZjW#
break; x $[_Hix
} ;.xKVH/@
} {*g{9`
F4"bMN
d:vc)]M>f{
public void splitterStop() `-cw[@uD
{ x[)]u8^A
bStop = true; 9An\uH)mL
} U6wy^!_X9
UUbO\_&y
t>LSP$
} ~#VDJ[Z
9vW]HOK
[g:cG
/* y4 ]5z/
**FileAccess.java z<^LY]
*//文件访问(定位，写) }M"])B I
package NetFox; g] ]6)nT
import java.io.*; =+?OsH v
s S3RK
vg@5`U`^h
public class FileAccessI implements Serializable{ 9C Ki$L
,JbP~2M~%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m:~y:.
RandomAccessFile oSavedFile; c68y\
long nPos; 5A5t
-#G>`T~
,Csjb1
public FileAccessI() throws IOException P*%P"g
{ c=?6`m,"M
this("",0); i|,}y`C#
} vF~q".imC
Tj!\SbnA[
3fX_XH1Q
public FileAccessI(String sName,long nPos) throws IOException N7}3?wS
{ <"3${'$k`
oSavedFile = new RandomAccessFile(sName,"rw"); PBEi"`i
this.nPos = nPos; -bSM]86
oSavedFile.seek(nPos); Pf?&ys6
} CK|AXz+EN
VG$;ri>
car|&b
public synchronized int write(byte[] b,int nStart,int nLen) p/7'r
{ O}2/w2n
int n = -1; e0ni
try{ eLgq )
oSavedFile.write(b,nStart,nLen); XDyo=A]
n = nLen; gcO$T`
} & @_PY
catch(IOException e) nUX3a'R
{ |yp^T
e.printStackTrace (); )Spa F)N8
} D^p)`*
*>Bew
" ;T a8
return n; HFFrS%
} QuI!`/N)z
|f1^&97=+
jA~omX2A
} SdMLO6-
>\J<`
1P'L<z
/* 8I#^qr5
**SiteInfoBean.java '"LaaTTs
*/ hcYqiM@8>
package NetFox; d1t_o2
+7 j/.R
4f~q$Sf]<
public class SiteInfoBean { lg ,%
QGGBI Ku
(G$Q\>
private String sSiteURL; //Site's URL =,qY\@fq
private String sFilePath; //Saved File's Path iYw1{U
private String sFileName; //Saved File's Name O*]}0*CT
private int nSplitter; //Count of Splited Downloading File 0(Z:QqpU$
e.XD5~Ax
H.]<fvP
public SiteInfoBean() KIWHn_ :
{//nSplitter的缺省值为5 -*ZQ=nomN
//default value of nSplitter is 5 xdaq` ^Bbt
this("","","",5); d|~'#:y@
} @;{ZnRv14
x{So
'0_W<lGB
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $rbr&TJ
{ T?jN/}qg
sSiteURL= sURL; tO1k2<Z"Y&
sFilePath = sPath; .A6pPRy e
sFileName = sName; 9asA-'fZ
this.nSplitter = nSpiltter; (sH4T>
9U3}_
E(1G!uu<
} CQ Ei(ty
10r!p:D
**AkpV)
public String getSSiteURL() yOXEP
{ maQxU(
return sSiteURL; e8xNZG;
} Pd `~#!
xH,e$t#@@~
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public void setSSiteURL(String value) |m*l/@1
{ >lek@euqw
sSiteURL = value; I)r6*|mz
} !B9Yw/Ba
H ]](xYy.
9q&~!>lt
public String getSFilePath() gF293Ez
{ Q4S:/"*v8
return sFilePath; +R{~%ZTK
} .>_%12>
^Mhh2v
vJ 28A
public void setSFilePath(String value) XMxm2-%olP
{ M9~'dS'XI
sFilePath = value; f= }!c*l"
} d:cOdm>,
GlJOb|WOX
Dd, &a
public String getSFileName() 0Am\02R.C,
{ B_8JwMJu3
return sFileName; KRP6b:+4L
} P~x4h{~Gd
Zk|PQfi+
)`gxaT>&l
public void setSFileName(String value) H3iYE~^#
{ KMl3`+i
sFileName = value; 9>&p:+D
} &=T>($3r94
'b>3:&
h{jm
public int getNSplitter() W>b\O">
{ fti0Tz'
return nSplitter; _KyhX|
} Ar_Yl|a
o(D_ /]'8
@|OGxQoC
public void setNSplitter(int nCount) ! 8Ro5),
{ W~l.feW$i
nSplitter = nCount; #0^a-47PA<
} N?A}WW#
} K,P`V &m?
C&EA@U5X^
AnZy oa
/* `J7@G]X;2
**Utility.java }<'ki ;
*/ tv]9n8v
package NetFox; =*6H!bzX
9Nz}'a;?>
4>B=k
public class Utility { (Bpn9}F-V.
DD>n-8M@>
<p` F/p-
public Utility() Dv^M/z2&[
{ k@>(sXs
)hVn/*mH
ys7Tq+
} y^ st T^
0juP"v$C>
//线程睡眠 HA&hu/mw_
public static void sleep(int nSecond) s4=EyBI
{ AJ#YjkO>]
try{ H>-{.E1bG
Thread.sleep(nSecond); RH$YM `cZ
} .8[uEQ_L
catch(Exception e) kD((1v*D$
{ 7Fzr\&
e.printStackTrace (); 6J-=6t|
} \t=#MzjR
} (d.M} G
>Wd_?NaI
//日志 ^7*zi_Q
public static void log(String sMsg) W}Rzn
{ UMPW<>z
System.err.println(sMsg); /(%!txSNEt
} CRNt5T>qH
C_h$$G{S(
6y{CM/DC
public static void log(int sMsg) TeJ=QpGW2
{ ArT@BqWd
System.err.println(sMsg); q$<VLrx
} "5\6`\/
} }/L#<n`Z
*A0d0M]cg
8>I4e5Ym
/* vnlHUQLO
**TestMethod.java t7e7q"+/
*/ ow'CwOj$
package NetFox; '_91(~P
b<E78B+Aax
u})8)
public class TestMethod { |2jA4C2L}
nHLMF7\
xd4~[n\hm
public TestMethod() =W gzj|Kr
{ ///xx/weblogic60b2_win.exe 0R-W9qP
try{ )]zsAw`/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); < 7*9b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ;2gO(
SiteFileFetch fileFetch = new SiteFileFetch(bean); "_+8z_
fileFetch.start(); p$Floubh]
} CX]L'
catch(Exception e){e.printStackTrace ();} gL7rX aj
j:HIcCp
m:9|5W
} y7Hoy.(
A^\g]rmK
/%bnG(4
public static void main(String[] args) B~YOU3
{ /3;]e3x
new TestMethod(); !~xlze
} /.t1Ow
} yQN^F+.
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