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)); WIG=D{\Yx
} Tq#<Po $
for(int i=0;i<nEndPos.length-1;i++) -l JYr/MSL
{ xFwXW)
nEndPos = nStartPos[i+1]; 27iy4(4
} @h(!<Ux_
nEndPos[nEndPos.length-1] = nFileLength; c'rd$
} ~6sE an3p
} 7E(%9W6P
4>_d3_1sn
waQtr,m)
//启动子线程 rhoeZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x.\XUJ4x
for(int i=0;i<nStartPos.length;i++) lY,/W
{ +5-fk>o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZpWu,1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), .[,6JU%
nStartPos,nEndPos,i); 6|oWaA\gI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }{mG/(LX8
fileSplitterFetch.start(); 045\i[l=
} p%8v`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !-RwB@\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !7c'<[+Hm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zAI|Jv@
nEndPos = " + nFileLength); b^Z$hnh]S
// fileSplitterFetch[nPos.length-1].start(); }$:#+ (17
I%i:)6Un-y
>2Ca5C
//等待子线程结束 \k4pK &b
//int count = 0; |z+9km7,
//是否结束while循环 +f|6AeE
boolean breakWhile = false; IfB/O.;Kz
*]2R.u
C fSl 54
while(!bStop) n}:t<
{ 9gR.RwR X
write_nPos(); !o<ICHHH
Utility.sleep(500); "&Mou
breakWhile = true; A;T[['
K7Gm-=%
}9=2g`2Q
for(int i=0;i<nStartPos.length;i++) ]ViOr8u
{ iD`k"\>9
if(!fileSplitterFetch.bDownOver) 8nsZ+,@+[
{ ]738Z/)^
breakWhile = false; >-zkB)5<,#
break; M5 `m.n<
} ^]7,1dH}M
} Qg>0G%cXU
if(breakWhile) x ^[F]YU
break; 4oN${7k0
~v\hIm3=m
s ^3[W0hL
//count++; #s{aulx
//if(count>4) (Com,
// siteStop(); EZ{/]gCK
} Z8fJ{uOIL
esteFLm`6
z^3Q.4Qc6^
System.err.println("文件下载结束！"); '%ebcL
} Efvq?cG&
catch(Exception e){e.printStackTrace ();} CrO`=\
} 1vsu[n
6}STp_x
JaFUcpZk$
//获得文件长度 eQ\jZ0s;p
public long getFileSize() 6y9C@5p}B
{ u?Z <n:
int nFileLength = -1; 9N1#V K
try{ [9HYO
URL url = new URL(siteInfoBean.getSSiteURL()); {NV:|M!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \=Nm5:
httpConnection.setRequestProperty("User-Agent","NetFox"); v~aLTI
0# l#,Y6#I
Th/{x h
int responseCode=httpConnection.getResponseCode(); /ISLVp%H
if(responseCode>=400) (JU_8j!
{ W]@6=OpH
processErrorCode(responseCode); 5y}BCY2=/
return -2; //-2 represent access is error KqK9X
} jiq2x\\!
7$#rNYa,z
3t*#!^$
String sHeader; %i3{TL
j9>TTgy@
wB2}uk7
for(int i=1;;i++) mZE8.`
{ w#<p^CS
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "4RQ`.SR
//Utility.log(in.readLine()); }>,CUz
sHeader=httpConnection.getHeaderFieldKey(i); p>&S7M/9
if(sHeader!=null) -tMA
{ LGfmUb-{]
if(sHeader.equals("Content-Length")) jJc07r']
{ >+SZd7p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >"b[r
break; aH
} kJ__:rS(T_
} ^6#-yDZC@
else . wmkj
break; 5v+L';wx[T
} ?eVj8 $BQo
} T$IUKR
catch(IOException e){e.printStackTrace ();} ~ttKI4
catch(Exception e){e.printStackTrace ();} wcl!S{
8UYJye8
VRB~7\A5<)
Utility.log(nFileLength); xRB7lV*
ozuIwzi7N
s|E%~j[9
return nFileLength; j<@fT ewZ
} W.p66IQwL&
T1bFxim#b
pW7kj&a_.
//保存下载信息（文件指针位置） );!dg\U
private void write_nPos() `^zQ$au'u
{ 0H<4+ *`K
try{ Z7oaQ\fR
output = new DataOutputStream(new FileOutputStream(tmpFile)); ho_4fDv
output.writeInt(nStartPos.length); rXuAixu!t
for(int i=0;i<nStartPos.length;i++) k0knPDbHv
{ (qbc;gBy
// output.writeLong(nPos); #.b^E3#+
output.writeLong(fileSplitterFetch.nStartPos); *.xZfi_|
output.writeLong(fileSplitterFetch.nEndPos); Stt* 1gT
} MorW\7-}
output.close(); IX?@~'
} t+J)dr
catch(IOException e){e.printStackTrace ();} zG<0CZQ8
catch(Exception e){e.printStackTrace ();} I0(8Z]x
} a 1NCVZ
zaBG=
^ISQ{M#_
//读取保存的下载信息（文件指针位置） $M-NR||k
private void read_nPos() Z<I[vp6{
{ Q+lbN
try{ "s${!A)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ir^BC!<2>
int nCount = input.readInt(); ^h`!f vyH
nStartPos = new long[nCount]; 8>m1UONr
nEndPos = new long[nCount]; ;}f6Y['z
for(int i=0;i<nStartPos.length;i++) o3fR3P%$
{ hg{ &Y(J!U
nStartPos = input.readLong(); M{G$Pk8[
nEndPos = input.readLong(); jXtLo,km
} o;%n,S8J|^
input.close(); lR,G;
} YyG~#6aCh
catch(IOException e){e.printStackTrace ();} vmMV n-\#
catch(Exception e){e.printStackTrace ();} A=W5W5l(>
} Na-q%ru
Up'."w_zE
V54q"kP,@.
private void processErrorCode(int nErrorCode) SK}HXG{?
{ WVinP(#nfM
System.err.println("Error Code : " + nErrorCode); B JU*`Tx
} 9Y\F53p&j
UUD\bWfn
JTjzT2`A.
//停止文件下载 ]gEu.Nth`
public void siteStop() ipfm'aQ
{ KzIt
bStop = true; G;Us-IRZ
for(int i=0;i<nStartPos.length;i++) 1O|RIv7F[/
fileSplitterFetch.splitterStop(); n|J.)E.
|b,zw^!e['
Dxz5NW4
} C CLfvex
} eK\|SQb
//负责部分文件的抓取 py}.00it
**FileSplitterFetch.java WT I'O
*/ .HQVj'g
package NetFox; on6<l
.0?ss0~
xu`d`!Tx
import java.io.*; Vvxa.B
import java.net.*; 3LT+9ad2d
t CkoYrvT
anpJAB:1
public class FileSplitterFetch extends Thread { 7=L:m7T
)H.ubM1
EUJ1RhajF
String sURL; //File URL .QNjeMu.
long nStartPos; //File Snippet Start Position }k4`
long nEndPos; //File Snippet End Position Z3Bo@`&?
int nThreadID; //Thread's ID (/To?`
boolean bDownOver = false; //Downing is over t*eleNYeS~
boolean bStop = false; //Stop identical O7!fI'R
FileAccessI fileAccessI = null; //File Access interface UUZ6N ZQI
e=0l<Rj
:v|r=#OI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C#ZmgR
{ $:xF)E
this.sURL = sURL; -WQ_[t9l
this.nStartPos = nStart; uPM8GIvZX.
this.nEndPos = nEnd; O_qu;Dx!
nThreadID = id; Z3LQl(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c1gz#,
} YK(XS"Kl
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vcaBL<io
public void run() {yGZc3e1j
{ Kc%tnVyGh:
while(nStartPos < nEndPos && !bStop) Z $ p^v*y
{ )6PJ*;p-
BDarJY
`;zu1o
try{ Xi1q]ps
URL url = new URL(sURL); mrhsKmH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2<p5_4"-U*
httpConnection.setRequestProperty("User-Agent","NetFox"); FSI]k:
String sProperty = "bytes="+nStartPos+"-"; ,Zf :R
httpConnection.setRequestProperty("RANGE",sProperty); O6M}W_
Utility.log(sProperty); >u'/$k
>#Grf)@"6
dqIZ#;:g
InputStream input = httpConnection.getInputStream(); D}=/w+
//logResponseHead(httpConnection); |JirBz
@n5;|`)\
*[XN.sb8E
byte[] b = new byte[1024]; xCDA1y;j
int nRead; Fh*q]1F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @5<]W+jk4
{ O>)n*OsS
nStartPos += fileAccessI.write(b,0,nRead); ;m2"cL>{l
//if(nThreadID == 1) }I` ku.@5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zsR wF
} hX{g]KE>
==PQ-Ia
V{ 4i$'
Utility.log("Thread " + nThreadID + " is over!"); B}l}Aq8
bDownOver = true; S,d ngb{
//nPos = fileAccessI.write (b,0,nRead); jQH5$
} =B3!jir
catch(Exception e){e.printStackTrace ();} x= vE&9_u
} ,qBnqi[
} jSUAU}u!M
PHe~{"|d?
o O{|C&A
//打印回应的头信息 LaEX kb*s
public void logResponseHead(HttpURLConnection con) l^!0|/Vw
{ "-~D!{rS
for(int i=1;;i++) 5~<a>>
{ IPr*pQ{;c
String header=con.getHeaderFieldKey(i); (;Dn%kK
if(header!=null) Z L6~Eut
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :N+K^gI)
Utility.log(header+" : "+con.getHeaderField(header)); p``;!3~~
else SopNtcu!
break; Vsm%h^]d
} A{{q'zb!
} q\z=z$VR
v4Fnh`{
Gdc~Lh
public void splitterStop() &VZmP5Gv
{ !h`cXY~w
bStop = true; _{Fdw
} w<I5@)i|
s%S_K
D>"{H7mY
} Qw{\sCH>
~#N.!e4
>%jEo'0;_
/* 3;-@<9
**FileAccess.java Jnu}{^~
*//文件访问(定位，写) TQbFI;\
package NetFox; /ut~jf`
import java.io.*; UG^?a
*x#&[>
tnKpn-LPA
public class FileAccessI implements Serializable{ O>o}<t7
k:+)$[t7
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uP%;QBb
RandomAccessFile oSavedFile; 5,=B1
long nPos; an[3vKb
X&FuqB
aQym= 6%e
public FileAccessI() throws IOException L(!!7B_,
{ X-;Qorb^
this("",0); ^V0{Ew/x
} c5mhl;+'
M~g~LhsF
dWq/)%@t
public FileAccessI(String sName,long nPos) throws IOException )W}/k$S
{ ]B-$p p
oSavedFile = new RandomAccessFile(sName,"rw"); .$ P2W0G
this.nPos = nPos; Mh-*5Rx
oSavedFile.seek(nPos); B3g82dm
} 9-Nq[i"
,P; a/{U
[/fwt!
public synchronized int write(byte[] b,int nStart,int nLen) {pQ@0b
{ u;'<- _
int n = -1; *nUpO]
try{ c|;|%"Mk
oSavedFile.write(b,nStart,nLen); !Z0rTC3d
n = nLen; wEHrer
} G+QNg.pH
catch(IOException e) CrwcYzrRWl
{ ]`i@~Z h\
e.printStackTrace (); 2'UFHiK
} @qr3v>3X<
E't G5,/m
_.J[w6
return n; ~"<VUJ=Ly:
} p?`|CE@h7
+<9q]V
$=QGua V
} (82\&dfy
KiRt'
@)juP- o%
/* 2Ws/0c
**SiteInfoBean.java r1az=$
*/ Cak/#1
package NetFox; C&s }m0R
/x8C70W^
:]z-Rz
public class SiteInfoBean { zHum&V8=H
{;(g[H=q;
G4J6
private String sSiteURL; //Site's URL _ry En
private String sFilePath; //Saved File's Path !k??Kj
private String sFileName; //Saved File's Name x8rFMR#S=
private int nSplitter; //Count of Splited Downloading File X#NeB>~
pra-8z-
)]>Y*<s }
public SiteInfoBean() __zu-!v
{//nSplitter的缺省值为5 Sy0s`\[
//default value of nSplitter is 5 [sO<6?LY
this("","","",5); <"|<)BGeI
} rgvc5p
"a`0w9Mm}
*,XJN_DKj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s:Ql](/B#
{ ht cO ~b
sSiteURL= sURL; F]&J%i F[
sFilePath = sPath; &#b>AAx$2Y
sFileName = sName; <~8f0+"
this.nSplitter = nSpiltter; -_f0AfU/a
#uw*8&%0
fdEj#Ux<H
} g:e8i~
aFc'_FrQ
Y(!)G!CMc
public String getSSiteURL() UmI@":|-
{ YU\t+/b
return sSiteURL; +7vh__
} }lvP|6Y: y
@_(@s*4W
J<$'^AR9"q
public void setSSiteURL(String value) 4}YT@={g}
{ #?d>S;)+
sSiteURL = value; Ywb)h^{!
} {ZYCnS&?CL
6Q?6-,?_
(i~%4w=
public String getSFilePath() D '_#?%3^
{ Yiw^@T\H`
return sFilePath; 7X3l&J2C4l
} 8; N}d)*O
owVUL~
] j?Fk$C
public void setSFilePath(String value) V@xnz)^t
{ UY& W]
sFilePath = value; {$eZF_}Y^
} >v4~:n2D
W)P_t"'@L
Vm8_ !$F
public String getSFileName() <YNPhu~5
{ o;-!?uJ
return sFileName; 2{tJ'3
} L=Jk"qWV0
dz.MH
9-<V%eNX
public void setSFileName(String value) [0 f6uIF
{ rTiuQdvo
sFileName = value; bL#TR;*]
} fOfz^W
Fi=8B&j
:[?o7%"
public int getNSplitter() 'GO..m"G
{ ,O`*AzjS5Q
return nSplitter; QO^X7A"?X
} tKViM@T
;+Kewi;<
p2?+[d
public void setNSplitter(int nCount) /r{5Lyk*
{ lMf5F8
nSplitter = nCount; s-DL=MD
} vK>^#b3
} ] :#IZ0#
lGgKzi9VD
c{P`oB8
/* `^h##WaXap
**Utility.java oRF"[G8BV
*/ iiFKt(
package NetFox; AiI# "
~Q\ZDMTK
Q$5:P&
public class Utility { (ZSSp1Rv
'0]_8Sy&
!|QeYGnq6
public Utility() @Oay$gP{T
{ At|tk
~ ?_Z!eS
t$5]1dY$X
} 9!C?2*>A P
Z'kYf
//线程睡眠 d> AmM!J
public static void sleep(int nSecond) iR=aYT~
{ ~ZC=!|Q#
try{ /T(~T
Thread.sleep(nSecond); k&;L(D
} xfSvvCy
catch(Exception e) *9&YkVw~
{ ar}759
e.printStackTrace (); -"L6^IH7
} &y?B&4|hM
} 8TvPCZ$x
SSC!BcC1
//日志 MUl+Oy>
public static void log(String sMsg) b=l}|)a
{ ]TOY_K8"z#
System.err.println(sMsg); VX%\_@
} /L Tyiiz6
6K0*?j{;"
A1;t60z+q>
public static void log(int sMsg) nClU5
{ Agf!6kh
System.err.println(sMsg); >D aS*r
} 2p ,6=8^v
} [: j_Y3-9
/q]@|5I
M 4?3l
/* V>SA3
**TestMethod.java (*gpa:Sc
*/ &6EfybAt^_
package NetFox; Br??Gdd
Pl6=._
]x\wP7x
public class TestMethod { d(XWt;KK
1OL~)X3
VG^-aR_F
public TestMethod() wH<*
{ ///xx/weblogic60b2_win.exe 1vb0G;a;|
try{ \_'pUp22
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )9->]U@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); de=T7,G#
SiteFileFetch fileFetch = new SiteFileFetch(bean); jd*H$BU^
fileFetch.start(); i[n1}E.@
} -nSqB{s!SD
catch(Exception e){e.printStackTrace ();} WI3!?>d
)]R8 $S
"bH ~CG:Y
} q<7n5kJ~
2{N0. |5
0qd`Pf
public static void main(String[] args) |<$O5b'
{ kA0^~
new TestMethod(); Lf9h;z>#
} ^g\%VIOD
} Y8T.RS0
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