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)); _urG_~q
} c ]>DI&$;J
for(int i=0;i<nEndPos.length-1;i++) 6OL41g'
{ lSH ZV Fd
nEndPos = nStartPos[i+1]; XkPv*%Er8
} XC|*A$x,
nEndPos[nEndPos.length-1] = nFileLength; )v%l0_z{
} F:M>z=
} 6xH;:B)d
X=v~^8M7%
&Nc[$H7<
//启动子线程 )@}A r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fL!V$]HNt
for(int i=0;i<nStartPos.length;i++) T/[f5?p
{ UTZ776`S&X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DH5bpg&T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b,#`n
nStartPos,nEndPos,i); 8y$5oD6g9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m</]D WJ
fileSplitterFetch.start(); }>2t&+v+
} gaQ[3g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w{PUj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L-#e?Y}$J
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (O$}(Tn
nEndPos = " + nFileLength); D=$4/D:;
// fileSplitterFetch[nPos.length-1].start(); }@d>,1DU
pe|X@o
'gCJ[ce
//等待子线程结束 gs?8Wzh90*
//int count = 0; :'Zx{F`
//是否结束while循环 3 m6$YWO
boolean breakWhile = false; d]U`?A,
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6`acg'sk>
while(!bStop) o`idg[l.
{ K[kds`
write_nPos(); a$d:_,\"
Utility.sleep(500); G.E[6G3
breakWhile = true; 70_}S*T
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for(int i=0;i<nStartPos.length;i++) Cl,9yU)1n
{ elu=9d];@
if(!fileSplitterFetch.bDownOver) )1WMlG
{ jh[ #p?:
breakWhile = false; H"eS<eT
break; 13H;p[$
} ;AKwx|I$g
} Hb+X}7c$
if(breakWhile) !x>,N%~
break; 69>/@<
ymYBm:"
6 Ew@L<v
//count++; RT,:hH
//if(count>4) a"x}b
// siteStop(); bl=ku<}@
} GMl"{Oxo&
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]Ko^G_Rm
System.err.println("文件下载结束！"); Xh?4mKgu
} P$_&
catch(Exception e){e.printStackTrace ();} K4: $=
} +~N!9eMc
=~&VdPZ
)>V?+L5M
//获得文件长度 9UV9h_.x
public long getFileSize() U9 #w
{ =-w;zx
int nFileLength = -1; xYPxg!
try{ hUh+JW
URL url = new URL(siteInfoBean.getSSiteURL()); eTT)P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h h"h j
httpConnection.setRequestProperty("User-Agent","NetFox"); vwmBUix
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{=67XrWN1
int responseCode=httpConnection.getResponseCode(); }AlYNEY
if(responseCode>=400) onwjn+"&
{ l-<`m#/v
processErrorCode(responseCode); lbTV$A
return -2; //-2 represent access is error V4|uas{0I:
} 5X#E@3g5
HJIC<U
\|.7-X
String sHeader; Tg0CE60"
yrnv!moc%t
`rlk|&T1
for(int i=1;;i++) 0]B(a
{ ?^}_j vT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +>SRrIi
//Utility.log(in.readLine()); ZIDbqQu
sHeader=httpConnection.getHeaderFieldKey(i); _|A+) K
if(sHeader!=null) {]^O:i"
{ {WQq}-(
if(sHeader.equals("Content-Length")) ygzxCn|#
{ <.bRf
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1Ipfw
break; Xh F_]
} %Ds+GM-
} Ab2Q \+,
else I-kWS4
break; d$G}iJ8$mp
} 8PBvV[
} ?T!)X)A#
catch(IOException e){e.printStackTrace ();} @}&_Dvf
catch(Exception e){e.printStackTrace ();} ml0*1Dw
Z.1> kZ
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Utility.log(nFileLength); G69GoT
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rzUlO5?R=
return nFileLength; P6\6?am
} cE\>f8 I
!Ms[eB
yCP4r6X0
//保存下载信息（文件指针位置） pr&=n;_ n
private void write_nPos() /<{:I \<
{ Dd,2;#_
try{ [M%._u,
output = new DataOutputStream(new FileOutputStream(tmpFile)); dg_Gs>?2
output.writeInt(nStartPos.length); > 'i
for(int i=0;i<nStartPos.length;i++) A6!F@Ic[
{ A&"%os
// output.writeLong(nPos); ^x m$EY*Y,
output.writeLong(fileSplitterFetch.nStartPos); YlF%UPp
output.writeLong(fileSplitterFetch.nEndPos); H,y4`p 0
} -oP'4QVb
output.close(); \+ 0k+B4a
} =5x&8i
catch(IOException e){e.printStackTrace ();} &%mXYj3y5
catch(Exception e){e.printStackTrace ();} !RH.|}
} /.1.MssQM
!h`kX[:
KzV 2MO-$
//读取保存的下载信息（文件指针位置） f0>!qt
private void read_nPos() "@/62b
{ hgj <>H|
try{ 'xE _Cj
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ii&7rdoxe
int nCount = input.readInt(); t:)ERT")
nStartPos = new long[nCount]; e<cM[6H'D
nEndPos = new long[nCount]; !.TLW
for(int i=0;i<nStartPos.length;i++) +>\id~c(
{ MTOy8 Im
nStartPos = input.readLong(); 1:M@&1LYp
nEndPos = input.readLong(); 2%u;$pj
} g(|{')8?d
input.close(); T~4N+fK
} Qk1xUE
catch(IOException e){e.printStackTrace ();} OLC{iD#
catch(Exception e){e.printStackTrace ();} &ldBv_
} t2BL(yB
,|kDsR!
6#@ f'~s
private void processErrorCode(int nErrorCode) om h{0jA0
{ 7U|mu~$.!
System.err.println("Error Code : " + nErrorCode); n$n7-7
} ,yd=e}lQx
_zWfI.o
qIMA6u/
//停止文件下载 De&6 9
public void siteStop() O1'm@ q)
{ 2lVHZ\G
bStop = true; 36.N>G,
for(int i=0;i<nStartPos.length;i++) JW.=T)
fileSplitterFetch.splitterStop(); 9f+>ix,ek*
RsJ6OFcWV
Yz$3;
} $%R$G`.KM
} &<RpWAk{
//负责部分文件的抓取 ~m^ #FJu
**FileSplitterFetch.java Xx:F)A8O
*/ \</b4iR)LT
package NetFox; -Go 7"j
r.ZF_^y}+
jhbonuV_
import java.io.*; qqrq11W
import java.net.*; svf|\p>]H
jz58E}
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public class FileSplitterFetch extends Thread { M-V&X&?j
z7GTaX$d
\;u@"
String sURL; //File URL D,qu-k[jMI
long nStartPos; //File Snippet Start Position v[e:qi&fG
long nEndPos; //File Snippet End Position )B,|@ynu
int nThreadID; //Thread's ID 1K,1X(0rL8
boolean bDownOver = false; //Downing is over \^7C0R-hX
boolean bStop = false; //Stop identical OyV<u@[i
FileAccessI fileAccessI = null; //File Access interface L@`ouQ"sa
~w8JH2O
sm[94,26
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s,k
{ Sf5X3,Uw
this.sURL = sURL; p~HW5\4
this.nStartPos = nStart; D(-yjY8aG
this.nEndPos = nEnd; 4SPy28<f
nThreadID = id; h.O$]:N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s*U1
} $un?0S
`Qr%+OD
J]f3CU,<N
public void run() e@:sR
{ iu&wO<)+?
while(nStartPos < nEndPos && !bStop) AKMm&(fh%
{ ^P151*=D
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;qHOOT
try{ yE[#ze
URL url = new URL(sURL); r'QnX;99T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7$h#OV*@,
httpConnection.setRequestProperty("User-Agent","NetFox"); V,rq0xW
String sProperty = "bytes="+nStartPos+"-"; 3gd&i
httpConnection.setRequestProperty("RANGE",sProperty); OO[F E3F
Utility.log(sProperty); -'~LjA(
<! )**
S26MDLk`R3
InputStream input = httpConnection.getInputStream(); ~/.7l8)
//logResponseHead(httpConnection); $!&*xrrNM
aaD;jxT&M|
UG=K|OXWJ
byte[] b = new byte[1024]; "Ph^BUAb
int nRead; Sb~MQ_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #>Zzf
{ `{qG1
nStartPos += fileAccessI.write(b,0,nRead); [JF150zr
//if(nThreadID == 1) g=I8@m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )iFJz/n>
} /cU<hApK
o=0]el^A
=s<( P1|"
Utility.log("Thread " + nThreadID + " is over!"); M Y|w
bDownOver = true; yX~v-N!X
//nPos = fileAccessI.write (b,0,nRead); s%<eD
} [l,Ei?
catch(Exception e){e.printStackTrace ();} \7CGUB>L
} ai0XL}!+
} &x3VCsC\|
w^t/9Nasi
:9k Ty:
//打印回应的头信息 fW?o@vlO
public void logResponseHead(HttpURLConnection con) LD!Q8"
{ GvBHd%Ot
for(int i=1;;i++) 6?w0
{ +SwR+H)?
String header=con.getHeaderFieldKey(i); JQ"U4GVp
if(header!=null) ~6p[El#tS
//responseHeaders.put(header,httpConnection.getHeaderField(header)); JH7<
Utility.log(header+" : "+con.getHeaderField(header)); &RfC"lc
else ocs+d\
break; 1dK*y'rx
} -Z's@'*
} =Q\r?(Iy
D*lKn62
K5lmVF\$P
public void splitterStop() jYKor7KTqT
{ fk&8]tK4
bStop = true; ^pUHKXihD
} >p"c>V& 8
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-,U3fts
} NU0g07"
F]<Xv"
o_~eg8
/* ?nL.w
**FileAccess.java d@qsdYu-*
*//文件访问(定位，写) >D4#y
package NetFox; d QqK^#
import java.io.*; Oeok;:
`^)jLuyu
DP|D\+YyYA
public class FileAccessI implements Serializable{ xoN3
i*Z"Me
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <*qnY7c&N;
RandomAccessFile oSavedFile; mGK|ihYu
long nPos; cI4K+
Q637N|01
`G}TG(
public FileAccessI() throws IOException (=om,g}
{ _WRFsDZ'
this("",0); B\XKw'
} sc}~8T
"/wyZ
bJX)$G
public FileAccessI(String sName,long nPos) throws IOException @"^0%/2-
{ hbY5l}\5
oSavedFile = new RandomAccessFile(sName,"rw"); N'GeHByIT
this.nPos = nPos; |EJD3&
oSavedFile.seek(nPos); BW$"`T@c6~
} (^Y~/
^y<<>Y'I
y#3j`. $3p
public synchronized int write(byte[] b,int nStart,int nLen) `)_dS&_\
{ r2,.abo
int n = -1; N(Fp0
try{ Tu).K.p:
oSavedFile.write(b,nStart,nLen); AHXSt
n = nLen; LhA/xf
} v]B3m
catch(IOException e) G?Q3/y(
{ N/MUwx;P
e.printStackTrace (); 8; 0A g
} e?8HgiP-
f,018]|
X\bOz[\
return n; ;)D];u|_
} ~T1XLu
M`,)wi
OCBgR4I
} JzQ)jdvp
uM_wjP
@`q:IIgW
/* h4T5+~rw
**SiteInfoBean.java lPw%ErG
*/ u>2 l7PA|
package NetFox; qVH1}9_
.\)U@L~
&m-PC(W+
public class SiteInfoBean { E87Ww,z8
E2R&[Q"%
6ZP(E^.
private String sSiteURL; //Site's URL LG9+y
private String sFilePath; //Saved File's Path l1BtI_7p
private String sFileName; //Saved File's Name {>hC~L?6
private int nSplitter; //Count of Splited Downloading File W3MJr&p
xMTKf+7
,(EO'T[
public SiteInfoBean() `p2+&&]S
{//nSplitter的缺省值为5 \hDlTp}
//default value of nSplitter is 5 H4:`6 PSL
this("","","",5); |}=acc/
} _Xk.p_uh
-?V-*jI
5Co
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F8jd'OR
{ -p]1=@A<}
sSiteURL= sURL; $w2u3-
sFilePath = sPath; &$`P,i 1)
sFileName = sName; F\KjEl0
this.nSplitter = nSpiltter; bDL,S?@
|H;F7Y_
Qz5sxi
} 6-$jkto
pwL;A3$|
< $J>9k
public String getSSiteURL() 49GkPy#]L=
{ .F
return sSiteURL; ,|y:" s
} WrQDX3
,(qRc(Ho
9g'LkP
public void setSSiteURL(String value) ?XrQ53
{ ;oW6 NJ
sSiteURL = value; mF*2#]%dx
} 0D\#Pq v
}X)&zenz
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public String getSFilePath() P5a4ze
{ Mo?~_|}
return sFilePath; V58wU:li
} 3!XjtVhK?I
$q6BP'7
Dz>^IMsY
public void setSFilePath(String value) )h"<\%LU
{ y{ibO}s
sFilePath = value; ^1iSn)&
} JEXy%hl
l=S35og
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public String getSFileName() re/@D@%
{ -]/I73!b
return sFileName; C'\- @/
} k1w_[w[
6& e3Nt
'\Giv!>
public void setSFileName(String value) {> eXR?s/
{ mn, =i
sFileName = value; }zkHJxZgE
} _<k\FU r
dgR g>)V
{MtpkUN
public int getNSplitter() 1C}NQ!.
{ CtyoHvw+M
return nSplitter; ciBP7>'::
} +giyX7BPJ
{@6=Q 6L
G`SUxhCk
public void setNSplitter(int nCount) K0-ypU*P
{ HePUWL'
nSplitter = nCount; 5]KW^sL
} |^:cG4e
} B~]k#Ot)
Aydm2!l1
)Xk0VDNp$/
/* 7C,&*Ax,9
**Utility.java O@u?h9?cf>
*/ Yw4n-0g
package NetFox; $7O}S.x
t[ubn+
tNO-e|~'
public class Utility { HJLu'KY}
M2PAy! J
`NCwK6/i
public Utility() CJ1 7n
{ fsJ9bQm/
U{7w#>V .
~HTmO;HNf"
} xf<at->
Bp_$.!Qy
//线程睡眠 tjIl-IQ
public static void sleep(int nSecond) a|%J=k>>
{ 9>l*lCA
try{ Ov5"
Thread.sleep(nSecond); w`4=_J=GO
} 7E!IF>`
catch(Exception e) ^8 zR
{ rf $QxJ
e.printStackTrace (); o)Iff)m$
} $;1#To
} )m`<H>[Eb=
Rn}l6kbM
//日志 gp5_Z-me
public static void log(String sMsg) *,e:]!*
{ ]JCvyz H
System.err.println(sMsg); zz+$=(T:M
} KC/=TSSXd.
-m)X]]~C
pOGeruu?
public static void log(int sMsg) }Ga\wV
{ gRCdY8GH
System.err.println(sMsg); 6g|*`x{
} d ^^bke$~
} C`$n[kCJ
l n{e1':$"
8K.R=
/* aoTM
**TestMethod.java r"C
*/ YM1'L\^
package NetFox; TT2d81I3m
LCZ\4g05
&|Bc7+/P
public class TestMethod { A#Iyb){Y
[BWNRC1
W=j[V Oq
public TestMethod() Cbg!:Cws
{ ///xx/weblogic60b2_win.exe FKIw!m ~
try{ f-bVKHt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h}*/Ge]aM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /j4P9y^]=
SiteFileFetch fileFetch = new SiteFileFetch(bean); ".W8)
fileFetch.start(); <vUbv
} Z3#P,y9@
catch(Exception e){e.printStackTrace ();} U}6B*Xx'
6ys &zy
iI\oz&!vH
} G'oG</A
S0B|#O%Z
Q9~*<I> h;
public static void main(String[] args) 1$D_6U:H0
{ T^Y([23
new TestMethod(); [h^2Y&Au5
} M^O2\G#B
} *C5R}9O5
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