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)); skaPC#u
} k|uW~I)
for(int i=0;i<nEndPos.length-1;i++) 80m<OW1
{ ;[nomxu|?
nEndPos = nStartPos[i+1]; xD.Uh}:J
} X 8/9x-E_
nEndPos[nEndPos.length-1] = nFileLength; 2><=U7~
} /6fa 7;
} X%X`o%AqC
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U~3uu&/r
//启动子线程 1PGY/c
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q' b@5o
for(int i=0;i<nStartPos.length;i++) 9!XXuMWU<
{ 4e`GMtp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V8KdY=[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xgp 6lO[
nStartPos,nEndPos,i); etw.l~y
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &[yW}uV<7
fileSplitterFetch.start(); 7=3'PfS
} |-)2 D=P
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v79k{<Ln
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S[zETRSG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mv,p*0
nEndPos = " + nFileLength); n3z]&J5fr
// fileSplitterFetch[nPos.length-1].start(); Z-U-n/6I
wn1` 9
qX9x#92
//等待子线程结束 L.ML0H-
//int count = 0; ^WF/gup\hS
//是否结束while循环 Q$bi:EyJXc
boolean breakWhile = false; 1`& Yg(
JX)%iJq#
wjzR 8g0bQ
while(!bStop) Qr.SPNUFK
{ n=F|bW
write_nPos(); OK]_.v}
Utility.sleep(500); rbt/b0ET
breakWhile = true; DYf3>xh>xb
(J6>]MZ#)
/}\Uw
for(int i=0;i<nStartPos.length;i++) y1qJ
{ faIHmU
if(!fileSplitterFetch.bDownOver) / biB*Z
{ N+N98~Y`P
breakWhile = false; Dve+ #H6N
break; "L9yG:
} #@UzOQ>
} aam6R/4
if(breakWhile) S"<"e\\}"_
break; ?9Hs,J
1 !8 b9
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//count++; b# |
//if(count>4) xg.o7-^M
// siteStop(); eAl;:0=%L
} rYI7V?
K@<%Vc>L(
Z#vU~1W
System.err.println("文件下载结束！"); 7Zw.mM!i
} 2kfX_RK
catch(Exception e){e.printStackTrace ();} )`z{T
} ,9.-A-Yw
}7HR<%<7
qdNt2SO
//获得文件长度 ISDeLUihY
public long getFileSize() +1pY^#A
{ 5H^"
int nFileLength = -1; ExxD w_VGT
try{ 0!tw)HR%
URL url = new URL(siteInfoBean.getSSiteURL()); ~Gj%z+<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !;, Dlq-}
httpConnection.setRequestProperty("User-Agent","NetFox"); M5Q7izM
d:!A`sk7
oMeIXb)z
int responseCode=httpConnection.getResponseCode(); Oz1S*<]=,~
if(responseCode>=400) b haYbiX?
{ U6xs'0
processErrorCode(responseCode); ;&} rO.0
return -2; //-2 represent access is error D.ERt)l>
} cii! WCu
5fvY#6;
X3zpU7`Av+
String sHeader; 0`Hr(J`F
T$IwrTF@?
lF#p1H>\
for(int i=1;;i++) W[SZZV_(tu
{ #V-0-n,`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B,(zp#&yB
//Utility.log(in.readLine()); S{fFpe-
sHeader=httpConnection.getHeaderFieldKey(i); 9g~"Y[ ]
if(sHeader!=null) 0[In5II
{ 61pJVOe
if(sHeader.equals("Content-Length")) _Squ%z:D
{ b-OniMq~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); GX#SCZ&}C
break; y!u=]BE
} *LOUf7`
} 1+ib(MJ<:#
else Ftw;T|
break; 3PUyua'
} c]PG5f xf
} TfnBPO
catch(IOException e){e.printStackTrace ();} %f1>cO9[
catch(Exception e){e.printStackTrace ();} .H#<yPty
UAEu.AT
UlQS]f~
Utility.log(nFileLength); tDQuimYu7
]9PQKC2&
Me2qOc^Z-
return nFileLength; VdOcKP.
} ; S~
oY<R[NYKu
'`sZo1x%f
//保存下载信息（文件指针位置） <HB@j}qi
private void write_nPos() k1E(SXcW9
{ kK~,?l
try{ ;hb_jW-0W
output = new DataOutputStream(new FileOutputStream(tmpFile)); PHR:BiMZ
output.writeInt(nStartPos.length); V.|#2gC]t
for(int i=0;i<nStartPos.length;i++) _ K Ix7
{ T*{nf
// output.writeLong(nPos); A+41JMH
output.writeLong(fileSplitterFetch.nStartPos); c-oIP~,
output.writeLong(fileSplitterFetch.nEndPos); bmQ-5SE
} ~-2Gx HO`
output.close(); 9$*O^
} bw8[L;~%_
catch(IOException e){e.printStackTrace ();} d:8c}t2X
catch(Exception e){e.printStackTrace ();} ^_c6Op<F
} #p7K2
]$&N"&q
`M[o.t
//读取保存的下载信息（文件指针位置） 6-Id{mx
private void read_nPos() rsn^YC
{ LTw.w:"J
try{ "I,=L;p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xrr3KQaK&
int nCount = input.readInt(); f!Mx +ky
nStartPos = new long[nCount]; o2rL&
nEndPos = new long[nCount]; S!8gy,7<J
for(int i=0;i<nStartPos.length;i++) G$A=Tu~
{ 0sfb$3y
nStartPos = input.readLong(); zVvL!
nEndPos = input.readLong(); *ry}T=
} -gB9476-
input.close(); :r4o:@N'
} -]Y@_T.C
catch(IOException e){e.printStackTrace ();} 2(AuhZ>
catch(Exception e){e.printStackTrace ();} 6wq>&P5
} W9!K~g_
{RC&Ub>
VRB!u420
private void processErrorCode(int nErrorCode) K_ Odu^
{ v3b+Ddp
System.err.println("Error Code : " + nErrorCode); e!=~f%c<N
} <j}A=SDZ)
He*c=^8k
]Ns)fr6
//停止文件下载 xG WA5[YV
public void siteStop() YL&)@h
{ Q!y%N&
bStop = true; `8/D$
for(int i=0;i<nStartPos.length;i++) &4{!5r
fileSplitterFetch.splitterStop(); ~@$RX:p
Sjp ]TWj
\b*z<Odv
} "A]#KTP
} yJ4ZB/ZQ
//负责部分文件的抓取 L*FQ`:lZ
**FileSplitterFetch.java y.$Ae1a=
*/ 8/k"A-m
package NetFox; gC+?5_=<
C7FxV2
6aKfcvf &
import java.io.*; nc^DFP
import java.net.*; fS$;~@p
:i>If:>g
HCw,bRxm
public class FileSplitterFetch extends Thread { h+ <Jv
ckYT69U
L+8{%\UPd
String sURL; //File URL *WfQi8
long nStartPos; //File Snippet Start Position CE@[Z
long nEndPos; //File Snippet End Position MdDL?ev
int nThreadID; //Thread's ID 5?q6g
boolean bDownOver = false; //Downing is over Y94S!TbB
boolean bStop = false; //Stop identical #z+?t
FileAccessI fileAccessI = null; //File Access interface {zalfw{+
;;|.qgxc~
4L_)@n}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zbI|3
{ )4TP{tp
this.sURL = sURL; E[cH/Rm
this.nStartPos = nStart; *yv@B!r
this.nEndPos = nEnd; F:og:[
nThreadID = id; 01~ nC@;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F+ %l= fs
} ERy=lP~gV
<HnpI
tl;b~k
public void run() 20# V?hX3
{ erhez
while(nStartPos < nEndPos && !bStop) @`qB[<t8:<
{ d ehK#8
,KCxNdg^#-
6Ey@)p..E
try{ ;!A=YXB
URL url = new URL(sURL); Y5c[9\'\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y/sZPG}4
httpConnection.setRequestProperty("User-Agent","NetFox"); 03c8VKp'p
String sProperty = "bytes="+nStartPos+"-"; ~owodc
httpConnection.setRequestProperty("RANGE",sProperty); K#Zv>x!to
Utility.log(sProperty); iK=QP+^VN
qOy0QZ#0
J0Gjo9L
InputStream input = httpConnection.getInputStream(); \CX6~
//logResponseHead(httpConnection); 2u$rloc$b
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( k,?)
byte[] b = new byte[1024]; 0xY</S
int nRead; pzZ+!d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9Dbbk/j|
{ }3_>
nStartPos += fileAccessI.write(b,0,nRead); _+X-D9j(l
//if(nThreadID == 1) _u]%K-_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CeeAw_*@
} n(`|:h"
"n_X4e+18P
"8R &c}
Utility.log("Thread " + nThreadID + " is over!"); c]n"1YNm
bDownOver = true; fW[ .Q0
//nPos = fileAccessI.write (b,0,nRead); 4xH/a1&p=
} FA+"t^q
catch(Exception e){e.printStackTrace ();} rsq?4+\
} ac\([F-
} Gt+rVJ=v
53 -Owjpx
^qzH(~g{M
//打印回应的头信息 Au6Y]
public void logResponseHead(HttpURLConnection con) )N*Jc @Y@
{ =t`cHs29
for(int i=1;;i++) }*C*!?pcd
{ 3I(;c ,S
String header=con.getHeaderFieldKey(i); K:^0*5Y-k
if(header!=null) `2hg?(ul
//responseHeaders.put(header,httpConnection.getHeaderField(header)); w {"1V7|
Utility.log(header+" : "+con.getHeaderField(header)); jwUX?`6jX
else I _gE`N
break; R1*4
} Z/dhp0k
} 4Us_Z{.
]x{.qTtw
r?IBmatK/
public void splitterStop() 0zE@?.
{ k(M:#oA!
bStop = true; QZtQogNy#
} x FWhr#5,
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lj UdsUw
} l&}}Io$?@
NSBcYObX
RWGf]V]6
/* TDUY&1[
**FileAccess.java #qh ,
*//文件访问(定位，写) \H~zN]3^
package NetFox; vP=68muD
import java.io.*; O=;jDWE
6T4I,XrY_F
|JP19KFx'B
public class FileAccessI implements Serializable{ *yaS^k\
:W5W @8Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _CfJKp)
RandomAccessFile oSavedFile; dFF=-_O>
long nPos; ,2^4"gIl
&w#!
c!_c, vwrn
public FileAccessI() throws IOException ?C#E_
{ ~MBPN4r
this("",0); \+l*ZNYM3
} Yj#tF}nPC
NcP/W>lN
tAF?.\x"g
public FileAccessI(String sName,long nPos) throws IOException '3Lu_]I-
{ OQ7 `n<I<)
oSavedFile = new RandomAccessFile(sName,"rw"); m3TR}=n
this.nPos = nPos; -^5467
oSavedFile.seek(nPos); K)BQ0v.:[
} 0/b _T
h%krA<G9
o6d x\
public synchronized int write(byte[] b,int nStart,int nLen) t*=[RS*
{ ATl?./Tu
int n = -1; _$ivN!k
try{ xH xTL>,?
oSavedFile.write(b,nStart,nLen); ~Ix2O
n = nLen; 'gvR?[!t
} X!p`|i
catch(IOException e) G$>QH-p
{ XTo7fbW*
e.printStackTrace (); ;Mup@)!j
} -cM1]soT
^J5{quV
IQRuqp KL
return n; v6s,lC5qR
} B*,)@h
0Gc@AG{
2S{P(B
} K5jt(7i
PDuc;RG
\xj;{xc
/* +yp:douERi
**SiteInfoBean.java :-B+W9'5
*/ P"8Ix
package NetFox; \3$!)z
u3C_Xz
MQQm3VaKS
public class SiteInfoBean { Lr:Qc#2
ch8a
z*EV>Y[
private String sSiteURL; //Site's URL ~w+I2oS$
private String sFilePath; //Saved File's Path gvA}s/
private String sFileName; //Saved File's Name (4T0U5jgT
private int nSplitter; //Count of Splited Downloading File y|2<Vc
G}fBd
@kWL "yy,
public SiteInfoBean() +e-F`k
{//nSplitter的缺省值为5 x#J9GP.
//default value of nSplitter is 5 OT%E|) 6'
this("","","",5); 94rSB}b.O
} j#1G?MF
lh8QtPe
P.'.KZJ:WD
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u^~7[OkE
{ 3m1(l?fp
sSiteURL= sURL; vR!+ 8sy$
sFilePath = sPath; JaCX}[R
sFileName = sName; m&:&z7^p
this.nSplitter = nSpiltter; zj1~[$ (
tWIs |n
9 {&g.+
} 0O9b 7F
C#kE{Qw10r
^#HaH
public String getSSiteURL() #ES[),+|mB
{ H<(F$7Q!\
return sSiteURL; p~ b4TRvA6
} %S`&R5
\c< oVF'
fF(2bVKP:
public void setSSiteURL(String value) ; oyV8P$
{ |ia5Mr"t
sSiteURL = value; eV[{c %wN:
} ;6W]f([
&h-_|N
VJ~D.ec
public String getSFilePath() wJy]Vyd
{ C!j3@EZ$
return sFilePath; "do5@$p|
} 3iCe5VF
S,c{LTL
rwRZGd *p
public void setSFilePath(String value) CS7b3p!I
{ u>*a@3$f
sFilePath = value; VeGSr
} r#sg5aS7O|
~#r>@C
aZN?V}^+
public String getSFileName() k=]e7~!
{ 79T_9}M
return sFileName; Uwc%'=@
} X:GRjoa
&C9IR,&
EYT^*1,E*
public void setSFileName(String value) j&8YE7
{ e~]P _53
sFileName = value; sL$sj|"S
} p&(0e,`z/
-9b=-K.y
\p4*Q}t
public int getNSplitter() cNWmaCLN$
{ $*C }iJsF
return nSplitter; w2s`9
} WLUgiW(0$
U%h.l
oGcgd$%ZB
public void setNSplitter(int nCount) JtFq/&{i
{ Y&6jFT_
nSplitter = nCount; `% 9Y)a/e
} |! 9~
} w <r*&
+(+lbCW/
xV> .]
/* Xf4QLw/r
**Utility.java /!]K+6>u
*/ *~PB
package NetFox; mdc?~??8
A;co1,]gR
-H60T,o
public class Utility { G*=HjLmZg
!VD$uT
b] 5dBZ(
public Utility() {"p ~M7
{ lQIg0G/3
mB`HPT
rEa(1(I
} Ku[q#_7
RuHDAJ"&a
//线程睡眠 zA#pgX[#
public static void sleep(int nSecond) b 8@}Jv
{ i+`8$uz
try{ ,a5q62)q
Thread.sleep(nSecond); 4Wl`hF
} ozOc6
catch(Exception e) so`\e^d
{ Xe4
e.printStackTrace (); qsj$u-xhX
} L` [iI
} z>!./z]p
s)\PY
//日志 4-bM90&1t
public static void log(String sMsg) RPX.?;":
{ \#[DZOI~
System.err.println(sMsg); [vr"FLM|9
} ]!ZZRe
! Vl)aL
l7t
public static void log(int sMsg) (6fD5XtS
{ -c>3|bo
System.err.println(sMsg); ndQw>
} BsA4/Bf
} Bl>m`/\1i
;1~n|IY
nKE^km
/* 5%TSUU+<I
**TestMethod.java N1Y uLG:
*/ @.L#u#
package NetFox; ^C K!=oO
|21VOPBS
X}GX6qAdt
public class TestMethod { rw)!>j+&A
Eq_@xT0>
24od74\
public TestMethod() IfH/~EtX
{ ///xx/weblogic60b2_win.exe $bhI2%_`M
try{ 'z91aNG]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p4uzw
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); U>n[R/~]
SiteFileFetch fileFetch = new SiteFileFetch(bean); V'b4wO1RV
fileFetch.start(); ^4IJL",
} I!!cA?W
catch(Exception e){e.printStackTrace ();} ;Qt%>Uo8
@CM5e!
0s8fF"$
} :H>I`)bw
I*3>>VN
[#!Y7Ede
public static void main(String[] args) q>+!Ete1p
{ NP3 e^
new TestMethod(); HMD\)vMK6
} E!X>C^
} ,./n@.na
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