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)); %.Ma_4o Z
} -B *W^-;*
for(int i=0;i<nEndPos.length-1;i++) C9!t&<\}
{ @-'a{hBR
nEndPos = nStartPos[i+1]; R}ki%i5|
} hMa;\k
nEndPos[nEndPos.length-1] = nFileLength; Y~WdN<g
} %_ibe
} jYHnJ}<
*nCA6i
QB*,+u4
//启动子线程 i6WH^IQM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nm-
for(int i=0;i<nStartPos.length;i++) j uA@"SG
{ wq$$. .E
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cZYy+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zm"
nStartPos,nEndPos,i); n#lbfN 4
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {]k#=a4
fileSplitterFetch.start(); mn7I# ~
} wJy]Vyd
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Mu\V3`j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3iCe5VF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rwRZGd *p
nEndPos = " + nFileLength); ~"#0rPT
// fileSplitterFetch[nPos.length-1].start(); hdPGqJE
%Mda<3P
r#sg5aS7O|
//等待子线程结束 cx\E40WD
//int count = 0; qGk.7wf%
//是否结束while循环 Q@VA@N=w
boolean breakWhile = false; WH:dcU
* Gg7(cnpw
Ew/MSl6}
while(!bStop) &C9IR,&
{ iWs6 !s!
write_nPos(); ;6G]~}>o
Utility.sleep(500); O[ma% E*0
breakWhile = true; v$y\X3)mB
kE&R;T`Gb%
ZISIW!
for(int i=0;i<nStartPos.length;i++) T:za},-
{ =Z\q``RBy
if(!fileSplitterFetch.bDownOver) 4uXGpsL
{ Dvg'
breakWhile = false; OrkcY39"~a
break; &FXf]9 _X
} kTL{Q0q
} Bhv;l/K])
if(breakWhile) ^E70$yB^
break; <Wn~s=
9q`Ewj R
QVT0.GzR
//count++; e>MtDJ5
//if(count>4) 2{ F-@}=
// siteStop(); |]&3*%b@
} LJeq{Z
#{6VdWZ
xWxHi6U(
System.err.println("文件下载结束！"); *~PB
} mdc?~??8
catch(Exception e){e.printStackTrace ();} A;co1,]gR
} -H60T,o
G*=HjLmZg
Y=XDN:
//获得文件长度 sp\6-*F
public long getFileSize() 6tH}&#K
{ ~VsN\!G
int nFileLength = -1; w7MRuAJ4
try{ x1@,k=qrd
URL url = new URL(siteInfoBean.getSSiteURL()); >WZ.Dj0n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F'uqL+jVO
httpConnection.setRequestProperty("User-Agent","NetFox"); :` SIuu~@
RuHDAJ"&a
zA#pgX[#
int responseCode=httpConnection.getResponseCode(); H:G``Vq;0m
if(responseCode>=400) D <iG*I
{ (%^C}`|EA
processErrorCode(responseCode); nAP*w6m0j
return -2; //-2 represent access is error K_MEd1l
} g2f"tu_/%
(Yy#:r;U
qsj$u-xhX
String sHeader; L` [iI
upMs yLp(
Y1Ql_
for(int i=1;;i++) {MtJP:8Jp
{ RPX.?;":
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \#[DZOI~
//Utility.log(in.readLine()); c44s@E
sHeader=httpConnection.getHeaderFieldKey(i); _N5pxe`
if(sHeader!=null) 27Gff(
{ =ls+vH40&
if(sHeader.equals("Content-Length")) JrBPx/?(,;
{ Yup#aeXY/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tar/no
break; R&!;(k0
} Wps^wY
} DcxT6[
else *$cx7yJ
break; %R5-6
} e/4C` J-
} m+M^we*R
catch(IOException e){e.printStackTrace ();} HL{aqT2
catch(Exception e){e.printStackTrace ();} <8(q.
ftn10TO*
@0@WklAJA
Utility.log(nFileLength); /R|?v{S1
Da<`| l
@Mya|zb
return nFileLength; U/Cc!WXV]
} dsX"S;`v
Lum=5zDo
1!zd#TX
//保存下载信息（文件指针位置） )7NK+k
private void write_nPos() VK/L}^=GOO
{ c6b51)sQ"
try{ X[/7vSqZ@w
output = new DataOutputStream(new FileOutputStream(tmpFile)); hGKQK ^bn
output.writeInt(nStartPos.length); Wt%Wpb8
for(int i=0;i<nStartPos.length;i++) /\,3AInLb
{ 7jw+o*;
// output.writeLong(nPos); uBG!R#T
output.writeLong(fileSplitterFetch.nStartPos); ce$[H}rDB
output.writeLong(fileSplitterFetch.nEndPos); g8/ ,E-u
} eJf]"-
output.close(); 8A0a/ 7Lj
} }#<Rs
catch(IOException e){e.printStackTrace ();} SOPair <r
catch(Exception e){e.printStackTrace ();} hcW>R
} $mT)<N ;w
/pRv i>_(:
.8'c c8
//读取保存的下载信息（文件指针位置） -I4@6vE,
private void read_nPos() ,]t_9B QK
{ A#`$#CO
try{ e6*,MnqBh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); |Fx *,91
int nCount = input.readInt(); xm=Gt$>.o
nStartPos = new long[nCount]; sw9ri}oc
nEndPos = new long[nCount]; 6lpJ+A57#
for(int i=0;i<nStartPos.length;i++) $J4)z&%dr
{ ~|<'@B!6
nStartPos = input.readLong(); 3ylSO73R
nEndPos = input.readLong(); ;pL!cG@
} y ~-v0/
input.close(); "O# V/(
} i\uj>;B
catch(IOException e){e.printStackTrace ();} IT#Li
catch(Exception e){e.printStackTrace ();} bR}fj.gP
} `s69p'<;p
k v_t6(qd
{^Q,G x(
private void processErrorCode(int nErrorCode) M:.+^.h
{ ]*MVC/R,
System.err.println("Error Code : " + nErrorCode); %O!xrA{
} F7<u1Rx]
3;jxIo$,
83]m/Iz
//停止文件下载 97HI9R
public void siteStop() ;wJe%Nw?
{ -~RGjx
bStop = true; e2fv%
for(int i=0;i<nStartPos.length;i++) X!{K`~DRX
fileSplitterFetch.splitterStop(); |7KWa(V5I
>tkz%;6
yFd.tQs
} }T PyHq"
} {\k }:)
//负责部分文件的抓取 `'3&tAy
**FileSplitterFetch.java w)&4i$Lk6
*/ eU)QoVt
package NetFox; G]$EIf'
6pb~+=3n
R@uA4Al
import java.io.*; \)6AzCq
import java.net.*; <l!:#u
tZx}/&m-
amExZ/
public class FileSplitterFetch extends Thread { s;l"'6:_
Q(Yn8t
cDYOJu.
String sURL; //File URL ]Ar,HaX-
long nStartPos; //File Snippet Start Position RnC+]J+?4
long nEndPos; //File Snippet End Position GJ`._ju
int nThreadID; //Thread's ID -Ju;i<
boolean bDownOver = false; //Downing is over ukVBC"Ny
boolean bStop = false; //Stop identical ue?3;BF 5
FileAccessI fileAccessI = null; //File Access interface a>-qHX-l
0t(c84o5
]1zud
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #l`\'0`.
{ 30SQ&j[N]
this.sURL = sURL; ~K5A$s2
this.nStartPos = nStart; QrFKjmD<
this.nEndPos = nEnd; Y^DGnx("m
nThreadID = id; 3.P7GbN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xf"< >M
} O8>&J-+2
raSga'uT;
rtbV*@Z
public void run() p(="73
{ AEx VKy
while(nStartPos < nEndPos && !bStop) 0Ntvd7"`}
{ l1`r%9gr
@(*A<2;N
3P>1-=
try{ Dk$<fMS,7c
URL url = new URL(sURL); Al@. KTK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3*\Q]|SI!
httpConnection.setRequestProperty("User-Agent","NetFox"); SHB'g){P
String sProperty = "bytes="+nStartPos+"-"; av5a2r0W1
httpConnection.setRequestProperty("RANGE",sProperty); >z/.8!#Q
Utility.log(sProperty); !%t2ZQJq
EbX!;z
j+dQI_']x
InputStream input = httpConnection.getInputStream(); ;; {K##^l
//logResponseHead(httpConnection); N(yd<Mw
vf#d
\et2aX !
byte[] b = new byte[1024]; 0WKS
int nRead; 4^YE*6z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cX4]ViXSr
{ K1R?Qt,qDF
nStartPos += fileAccessI.write(b,0,nRead); 9c*B%A8J
//if(nThreadID == 1) ")txFe
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9LBZMQ
} Dm}M8`|X
x@/:{B
F#)bGi
Utility.log("Thread " + nThreadID + " is over!"); ~#P]NWW%.
bDownOver = true; fI<d&5&g
//nPos = fileAccessI.write (b,0,nRead); ]91QZ~4a
} UU[z\^w| E
catch(Exception e){e.printStackTrace ();} zG/? wP"
} k?L2LIB<
} Ndb7>"W
qP&:9eL
B/;'D7i|S
//打印回应的头信息 %I!2dXNFRF
public void logResponseHead(HttpURLConnection con) '+vmC*-I(
{ r_,;[+!
for(int i=1;;i++) `jr?I {m;
{ Ya!%o> J%t
String header=con.getHeaderFieldKey(i); kw#-\RR_c
if(header!=null) %QGw`E
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Fsx<Sa
Utility.log(header+" : "+con.getHeaderField(header)); 75>Ok/
else .L"IG=Uh#
break; $)X8'1%6
} KUm?gFh
} P7Qel,
xYW&Mfka
@^.W|Zh[&
public void splitterStop() VlL%dN; 0
{ QX<x2U
bStop = true; [.Kp/,JY
} 1kvs2
#,6T.O
u-:3C<&>
} ; Ad5Jk
nfGI4ZE
kQlwl9
/* N]|>\
**FileAccess.java cL03V?} ~
*//文件访问(定位，写) rMZuiRz*
package NetFox; B@6L<oZ
import java.io.*; g*LD}`X/-
8 Zp^/43
t#t[cgI
public class FileAccessI implements Serializable{ SZ$WC8AX
>zL5*:G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m_Q&zp["
RandomAccessFile oSavedFile; _!, J iOI
long nPos; q-_!&kDK"
^->S7[N?
bJD$!*r\%!
public FileAccessI() throws IOException ysp`(n=
{ ey4.Hj#T
this("",0); NIbK3`1
} w7Y@wa!
02*qf:kTnA
8=joVbs
public FileAccessI(String sName,long nPos) throws IOException udLIAV*
{ 6j6;lNUc
oSavedFile = new RandomAccessFile(sName,"rw"); fxr#T'i
this.nPos = nPos; {N/%%O.b
oSavedFile.seek(nPos); sO6=w%l^
} yrfV&C%=n
r@Jy*2[-Jq
Yb/*2iWX
public synchronized int write(byte[] b,int nStart,int nLen) 9`Fw}yAt
{ s<k2vbhI
int n = -1; vPz7*w
try{ *x;4::'Jn
oSavedFile.write(b,nStart,nLen); :N$-SV
n = nLen; r-.@MbBm
} h"0)spF"d
catch(IOException e) u5glKE
{ ;`:YZ+2 Z
e.printStackTrace (); 1,bE[_
} ,#&7+e!]>P
5Lej_uqF
T>L?\-
return n; lG94^|U
} SZHgXl3:
pWJEFm
(?zD!% k
} <"P-7/j3j
hdrsa}{g
\y=oZk4
/* q^EY?;Y
**SiteInfoBean.java X|eZpIA45
*/ )S2yU<6oOt
package NetFox; s:"Sbml
xSK#ovH2
W [K.|8ho
public class SiteInfoBean { Xw!\,"{s
x4H#8ZK!
zp1ym}9M
private String sSiteURL; //Site's URL \P?X`]NwnO
private String sFilePath; //Saved File's Path VK1B}5/
private String sFileName; //Saved File's Name z^Ikb(KC
private int nSplitter; //Count of Splited Downloading File ozRTY9S _;
R( FQ+h
@y`xFPB
public SiteInfoBean() G`>]ng
{//nSplitter的缺省值为5 ^9q#,6
//default value of nSplitter is 5 g;8 wP5i
this("","","",5); _J W|3q
} er)I".|
Xzf,S;XV~
oYStf5
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @&O4a2+
{ HRDpFMA/~
sSiteURL= sURL; p.=9[`
sFilePath = sPath; wLXJ?iy3
sFileName = sName; U"p</Q
this.nSplitter = nSpiltter; `**{a/3
<c pck
tULGfvp
} bP9ly9FH
@3O)#r}\
`!HD. E[2c
public String getSSiteURL() "Nj/{BU
{ 4r1\&sI$~
return sSiteURL; &o;0%QgF
} x I.W-js[
}:ZA)
7D#y
public void setSSiteURL(String value) iT4*~(p 3
{ bhpku=ov
sSiteURL = value; U-u?oU-.'
} )P:^A9&_n=
IFX$\+-
cZ?QI6|[
public String getSFilePath() d-UeItyW*
{ s51$x M
return sFilePath; PWpt\g
} Lau@HYW0
;X,u
"[|b,fxR
public void setSFilePath(String value) e}e8WR=B
{ ns8s2kYcm
sFilePath = value; x 6`!
} "+"=iwEAz
+&`W\?.~
!=,4tg`
public String getSFileName() "S%t\
{ 1jl!VU6
return sFileName; E6A"Xo
} '3(^Zv
G-Tmk7m
|HAJDhM,l
public void setSFileName(String value) oY18a*_>M1
{ }p7iv:P=3
sFileName = value; }6c>BU}DF
} ijF_ KP'
ssi7)0
MePD:;mm^
public int getNSplitter() Nujnm$!,Q
{ WD[eoi
return nSplitter; >0IZ%Wiz
} ;hX(/T
vjGQ!xF
0Z9DewwP
public void setNSplitter(int nCount) Z.6dL
{ hi0HEm\
nSplitter = nCount; 8vY-bm,e
} >d2Fa4u3
} 5~JT*Ny
H$(bSw$
zN4OrG0
/* Ic#xz;elM
**Utility.java JQ&t"`\k
*/ 2d !'9mA
package NetFox; i<m(neX[H
\2i7\U
#&&T1;z"#
public class Utility { _>;Wz7
!Lf<hS^
V)`2Kw
public Utility() IY`p7 )#i
{ =?fz-HB
$<^t][{
Dm>"c;2
} IU%|K~_n
NI >%v
//线程睡眠 @w[i%F,&`
public static void sleep(int nSecond) iq(PC3e`V
{ 'pdTV:]zA
try{ XIHN6aQ{X
Thread.sleep(nSecond); _!\d?]Ya
} +2~kHrv
catch(Exception e) ,kN;d}bg
{ #<im?
e.printStackTrace (); 6[> lzEZ
} X*8y"~X|vq
} *v>ZE6CL
,5}U H
//日志 |\5^ub,m
public static void log(String sMsg) 0lfK} a
{ >H2`4]4]
System.err.println(sMsg); vT'Bs;QR
} !>8~R2
RK>Pe3<
K7+yU3
public static void log(int sMsg) WSkGVQu
{ =l,P'E
System.err.println(sMsg); AlSO
} 6OES'3Cy
} '|C3t!H`
ly[LF1t
E$e7(D
/* ~4S$+*'8
**TestMethod.java wbO6Ag@))
*/ C6_(j48&
package NetFox; ?Ec9rM\ze
RU)35oEV|
Y?VbgOM)
public class TestMethod { {f!/:bM
?9b9{c'an
+]db-
public TestMethod() }I"C4'(a
{ ///xx/weblogic60b2_win.exe kIrrbD
try{ (B7G'h.?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); \{,TpK.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); KhCP9(A=Qo
SiteFileFetch fileFetch = new SiteFileFetch(bean); v<qh;2
fileFetch.start(); iTVe8eI
} I$n=>s
catch(Exception e){e.printStackTrace ();} d"$8-_K
[|u^:&az
8sG3<$Z^
} $Gn.G_"v
:QCL9QZ'
^E !v D
public static void main(String[] args) #x%'U}sF
{ 90}{4&C.^
new TestMethod(); QFyL2Xes/
} mCtS_"W
} X'9.fKp
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