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)); OO?;??
} Ci-CY/]s
for(int i=0;i<nEndPos.length-1;i++) A#o ~nC<
{ zIzL7oD
nEndPos = nStartPos[i+1]; Y)O88C
} ugu|?z*dI
nEndPos[nEndPos.length-1] = nFileLength; YW14X
} x?"+Or.h
} T`zUgZ]
x/S:)z%X
mm dQ\\
//启动子线程 N9dx^+\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `{oFdvL~)
for(int i=0;i<nStartPos.length;i++) 5cUz^ >
{ ;b`kN;s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e,?qwZK:y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), nF5\iV
nStartPos,nEndPos,i); HZawB25{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y5ZBP?P
fileSplitterFetch.start(); 3wYhDxY1
} g[c_rty
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |j2$G~B6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7DZZdH$Fm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YHp]O+c
nEndPos = " + nFileLength); XLgp.w;
// fileSplitterFetch[nPos.length-1].start(); N,3 )`Vm
DqJzsk'd3
"C]v
//等待子线程结束 c]/X >8;
//int count = 0; S4Q fx6:~h
//是否结束while循环 Nx;Oz
boolean breakWhile = false; 17E,Qnf
#?h-<KQQ
&*Z"r*
while(!bStop) q/h, jM
{ ;u?L>(b
write_nPos(); (|2:^T+
Utility.sleep(500); Yq-Vwh/
breakWhile = true; l9Av@|
4T>d%Tt+)
3E-dhSz:i
for(int i=0;i<nStartPos.length;i++) 4n0Iw I
{ M:*)l(
if(!fileSplitterFetch.bDownOver) rqWD#FB=z
{ Z [YSET
breakWhile = false; ts/Ha*h
break; M\A6;dz'
} c6Z"6-}$
} o_sb+Vn|
if(breakWhile) ^2`*1el
break; j a'_syn
n[gc`#7|{e
AIG5a$}&
//count++; Oj>;[O"
//if(count>4) Y#zHw<<E
// siteStop(); Gm[XnUR7V
} {%D4%X<
P]0/S
> ofWHl[-
System.err.println("文件下载结束！"); YJF|J2u
} lNo]]a+_
catch(Exception e){e.printStackTrace ();} ,R}9n@JI^Y
} 4C }#lW9
f_z]kA +H
!>?*gc.<
//获得文件长度 tfdb9#&?
public long getFileSize() }_oQg_-7e
{ 5i-VnG
int nFileLength = -1; IOY<'t+
try{ *&~(>gNF,
URL url = new URL(siteInfoBean.getSSiteURL()); ,0@QBr5P
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6f^IAa|
httpConnection.setRequestProperty("User-Agent","NetFox"); M%bD7naBq
)C$pjjo/`
@2~;)*
int responseCode=httpConnection.getResponseCode(); M Al4g+es
if(responseCode>=400) YRyaOrl$<
{ skF}_
processErrorCode(responseCode); L5wR4Ue)
return -2; //-2 represent access is error ^|(VI0KO
} MDoV84Fh
XZ:6A]62I
~?Zm3zOCc2
String sHeader; Y+DVwz$
oml^f~pm
#'97mg
for(int i=1;;i++) H`4KhdqR
{ riQ0'-p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {$I1(DYN
//Utility.log(in.readLine()); L=gG23U&
sHeader=httpConnection.getHeaderFieldKey(i); @CS%=tE}U
if(sHeader!=null) A}[x))r
{ "}2I0tM
if(sHeader.equals("Content-Length")) Q>I7.c-M|
{ z,RjQTd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CQs,G8\/
break; p@eW*tE
} C,B{7s0-
} mM'uRhO+
else mZ g'
break; C6qGCzlG`
} A+KpECP
} -ZoAbp$
catch(IOException e){e.printStackTrace ();} UlPhW~F)
catch(Exception e){e.printStackTrace ();} y;fnC5Q
r`sG!
M63t4; 0A
Utility.log(nFileLength); )O8w'4P5
-0+h&CO
63VgQ
return nFileLength; IeAi'
} p: u@? k
l4YTR4D
y>c Yw!
//保存下载信息（文件指针位置） y m?uj4I{
private void write_nPos() H-3*},9
{ /}k?Tg/
try{ )BZ6QO`5n
output = new DataOutputStream(new FileOutputStream(tmpFile)); sY* qf=
output.writeInt(nStartPos.length); ~&D5RfK5f
for(int i=0;i<nStartPos.length;i++) B.}j1Bb
{ zd=N.
// output.writeLong(nPos); x,c\q$8yH
output.writeLong(fileSplitterFetch.nStartPos); _opB,,G
output.writeLong(fileSplitterFetch.nEndPos); $49;\pBZl
} #Eqx Eo;
output.close(); XdE|7=+s
} s0'6r$xj
catch(IOException e){e.printStackTrace ();} SP4(yJy&
catch(Exception e){e.printStackTrace ();} P&Wf.qr{:
} SmV}Wf
'jYKfq~_cJ
nq\~`vH|Gd
//读取保存的下载信息（文件指针位置） rxOvYF
private void read_nPos() HE-ErEtGB
{ Ah;`0Hz;
try{ X.AE>fx*h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hLaQ[9
int nCount = input.readInt(); F#z1 sl'
nStartPos = new long[nCount]; Fnuheb'&m
nEndPos = new long[nCount]; #'I<q
for(int i=0;i<nStartPos.length;i++) >vDi,qmZ
{ ])#?rRw
nStartPos = input.readLong(); ]Aj5 K
nEndPos = input.readLong(); ITZ}$=
} {5(M
input.close(); vofBS
} EJ(z]M`f
catch(IOException e){e.printStackTrace ();} NW`Mc&
catch(Exception e){e.printStackTrace ();} REPI>-|
} /}S1e P6
EQX?Zs?C
q&esI
private void processErrorCode(int nErrorCode) >fp_$bjd
{ VqS1n
System.err.println("Error Code : " + nErrorCode); VP^{-mDph
} o97*3W]
_xM3c&VeG
8COGe=+o
//停止文件下载 >[<f\BN|
public void siteStop() o`nJJ:Cxq-
{ |5*:ThC[
bStop = true; 0NXaAf:2Z
for(int i=0;i<nStartPos.length;i++) '\P+Bu]6&
fileSplitterFetch.splitterStop(); [6%y RQ_
?+L7Bd(EF%
Mlo:\ST|
} +<3e@s&
} ?Skv2!X|
//负责部分文件的抓取 ]:Pkh./
**FileSplitterFetch.java 1n#{c5T
*/ )H{OqZZYD
package NetFox; ;pG5zRe
<<&SyP
cUwR6I9
import java.io.*; `m\ ?gsw7
import java.net.*; R.rE+gxO1
@4>?Y=#
Q7_#k66gb7
public class FileSplitterFetch extends Thread { .8XkB<[wb
+XAM2uN5_.
fwSI"cfM
String sURL; //File URL RA}Y$}^#'
long nStartPos; //File Snippet Start Position `rpmh7*WV
long nEndPos; //File Snippet End Position v"dl6%D"
int nThreadID; //Thread's ID B \.05<
boolean bDownOver = false; //Downing is over US&:UzI.
boolean bStop = false; //Stop identical B~%SB/eu
FileAccessI fileAccessI = null; //File Access interface 9w-;d=(Q
! ~+mf^D
O>IG7Ujl
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "Jg* /F
{ d V3R)
this.sURL = sURL; T5aeO^x
this.nStartPos = nStart; "MDy0Tj8EN
this.nEndPos = nEnd; X`7O%HiX/`
nThreadID = id; Hm_&``='
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =j8g6#'u
} uy([>8uu
p%5(Qqmlk
p+Fh9N<F9
public void run() rrl{3 ?
{ WB"90!
while(nStartPos < nEndPos && !bStop) ;MW=F9U*
{ :Y4G^i
qR^+K@*|
C`\yc_b9Pf
try{ Q'rX]kk_
URL url = new URL(sURL); W1[C/dDc
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); sX(rJLbD
httpConnection.setRequestProperty("User-Agent","NetFox"); *!,k`=.([#
String sProperty = "bytes="+nStartPos+"-"; @XH@i+{B
httpConnection.setRequestProperty("RANGE",sProperty); Gk)6ljL
Utility.log(sProperty); g?>
Olr'n% }
KXcE@q9
InputStream input = httpConnection.getInputStream(); !{XVaQ?x
//logResponseHead(httpConnection); cB2~W%H
^F-AZP /5F
<#lNi.?.
byte[] b = new byte[1024]; Zrq\:KxX
int nRead; 6W)#FO`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tA-p!#V<k1
{ v#9Uy}NJ9
nStartPos += fileAccessI.write(b,0,nRead); qO>A6
//if(nThreadID == 1) vcSb:('
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MwWN;_#EO)
} NZuylQ)0
":L d}~>
Ar`U/ %Cu
Utility.log("Thread " + nThreadID + " is over!"); BsYJIKfW
bDownOver = true; _+qtH< F/
//nPos = fileAccessI.write (b,0,nRead); 2MDY nMy
} `%=!_|
catch(Exception e){e.printStackTrace ();} ];Y tw6A
} V.w!]{xm
} |L6 +e*
VpB+|%@p
*m&(h@l
//打印回应的头信息 jk5C2dy
public void logResponseHead(HttpURLConnection con) \5F {MBx !
{ U.J/ "}5`T
for(int i=1;;i++) ?DC;Hk<
{ &FDWlrGg
String header=con.getHeaderFieldKey(i); =2d h}8Mz
if(header!=null) }1YQ?:@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'l._00yu
Utility.log(header+" : "+con.getHeaderField(header)); _@sSVh$+
else ?YnB:z*eV
break; %kiPE<<x
} zC!Pb{IaH
} 8o,"G}Hjk
4M>EQF&
Y^'mBM#j
public void splitterStop() XI5q>cd\Sz
{ e;&fO[2
bStop = true; (&qjY I
} 8&v%>wxR@
{Pe+d3Eoo
bYy7Ul6]
} p;LF-R
:JzJ(q/
''B}^yKEW
/* kDWvjT
**FileAccess.java n<MreKixE
*//文件访问(定位，写) :SVWi}:Co1
package NetFox; 8z*/J=n
import java.io.*; g y1i%
\_|r>vQ
MW)=l | G
public class FileAccessI implements Serializable{ a`zw5
4"Pf0PD:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 oqy}?<SQ
RandomAccessFile oSavedFile; Q5tx\GE
long nPos; e`Tssa+
O+o_{t\R
~Q5 i0s%
public FileAccessI() throws IOException 8[H)tKf8
{ jR{Rd}QtQ
this("",0); ]D|Hq4ug
} m"mU:-jk`
O-]^_LV`
usI$
public FileAccessI(String sName,long nPos) throws IOException ~)iQbLI
{ G!w?\-
oSavedFile = new RandomAccessFile(sName,"rw"); ;Y`k-R:E6A
this.nPos = nPos; X8(WsN
oSavedFile.seek(nPos); mjbV^^>
} Y>PC>
r r(UE
JAI;7
public synchronized int write(byte[] b,int nStart,int nLen) q%k _C0
{ _eMY?
int n = -1; 9d&}CZr
try{ j'|`:^ Sy
oSavedFile.write(b,nStart,nLen); rfhvdwwD
n = nLen; };]f 3
} 4GqE%n+ta~
catch(IOException e) W>rx:O+
{ U,GY']J
e.printStackTrace (); TAZ+2S##7
} Dhp|%_>
fnudu0k
|%5nV=&\
return n; /SQ1i}%
} uzWz+atH
G>0hi1
[USE&_RN
} u YJL^I8M'
[7gwJiK
q<wQ/m
/* 1<3!
**SiteInfoBean.java =j S
*/ !gFUC<4bu
package NetFox; kIYV%O
&p:GB_
N!^5<2z@eT
public class SiteInfoBean { D^\2a;[AxA
2V=bE-
"3:TrM$|A
private String sSiteURL; //Site's URL $7bux1L
private String sFilePath; //Saved File's Path glP W9q,f
private String sFileName; //Saved File's Name pt- 1>Ui
private int nSplitter; //Count of Splited Downloading File +@5*_n\e`
xsSX~`
^_pJEX
public SiteInfoBean() 6*=7ifS
{//nSplitter的缺省值为5 PU^@BZ_m
//default value of nSplitter is 5 P(Ve' wOaf
this("","","",5); XpibI3:<
} xzTF| Z\
qn|~z@"
nV&v@g4Tt
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9U~sRj=D
{ $|r p5D6
sSiteURL= sURL; !x1ivP
sFilePath = sPath; s+XDtO
sFileName = sName; UqZ#mKi
this.nSplitter = nSpiltter; xEvm>BZi
T&~7*j(|e
xl;0&/7e
} c %.vI
\h 1T/_4
SjB#"A5
public String getSSiteURL() ]<?7CpP
{ mL[Y{t#N
return sSiteURL; *IBCThj
} k>q}: J9V
F5FzT^
YUsMq3^&
public void setSSiteURL(String value) m kHcGB!~
{ 3Mt Alc0xp
sSiteURL = value; It3.
} mY !LGN
<<.%Gk
7__?1n~{
public String getSFilePath() >@c~M
{ _4#&!b6
return sFilePath; y<A%&
} KHJk}]K
ZP^7`q)6
;IX*4E'4s
public void setSFilePath(String value) Z* L{;
{ H{nYZOf/
sFilePath = value; UAq%Y8KA
} Y;6%pm$
7O.{g
dw]wQ\4B
public String getSFileName() l9X\\uG&
{ T&PLvyBL
return sFileName; |8YP8o
} {r2fIj~V
[.`%]Z(
q^k]e{PD
public void setSFileName(String value) @ME .
{ N_Y*Z`Xb
sFileName = value; /l@h[}g+d-
} 2>!?EIE7
EU"J'?
<UMT:`h1MZ
public int getNSplitter() 37QXML
{ ]J* y`jn
return nSplitter; &9F(uk=X
} #\)tz z
yL>wCD,L
t=Um@;wh
public void setNSplitter(int nCount) ,t=12R]>
{ ,dO$R.h
nSplitter = nCount; )mbRG9P
} XU19+mW=P
} =YRN"
^#A[cY2eM
*b >hZkObn
/* %"> Oy&3
**Utility.java R1=ir# U|D
*/ mv+K!T6
package NetFox; }475c{
@lnM%
x6c#[:R&
public class Utility { <7%4=
WgK|r~
QP?Deltp
public Utility() $=-Q]ld&]
{ ']]&<B}mz
e;/C}sK:
MlM2(/ok
} %g<J"/
-=A W. Zo
//线程睡眠 /-W-MP=Wd
public static void sleep(int nSecond) > \KVg(?D
{ FTg4i\Wp
try{ m*^|9*dIC
Thread.sleep(nSecond); 4JD 8w3u/
} GqrOj++>
catch(Exception e) A|esVUo<3^
{ 9IRvbE~2
e.printStackTrace (); WZ<kk T
} OLdD3OI
} ,t]qe
<15POB
//日志 %$l^C!qcY
public static void log(String sMsg) -Jtx9P
{ 'C9H6)Zq)
System.err.println(sMsg); (BA2
} ;|Z;YK@20
Q&9%XF uM
>Lo!8Hen
public static void log(int sMsg) dWI.t1`i
{ $qx&\@O
System.err.println(sMsg); ;|hEXd?b
} 5w#*JK
} '%m0@5|hCD
7(<49bb.V
4P>tGO&*x
/* Uq,M\V\
**TestMethod.java N&0MA
*/ #NVqS5
package NetFox; YW}1iT/H
7\ <4LX
Jb~-)n2
public class TestMethod { a*pZcv<
G=8w9-Ww
JL9d&7-
public TestMethod() #&1Y!kbdd
{ ///xx/weblogic60b2_win.exe LaE;{jY
try{ %}=$HwN)
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1]@}+H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9@yP;{Q
SiteFileFetch fileFetch = new SiteFileFetch(bean); c#G]3vTdE
fileFetch.start(); s'^zudx
} ;!@\|E
catch(Exception e){e.printStackTrace ();} t#y
xX'Uq_Jv
ndm19M8Y|
} I_yIVw;
;UgRm#
L-d8bA
public static void main(String[] args) c=2e?
{ *x| <\_+
new TestMethod(); L!L/QG|wdf
} DJE/u qE
} wS2iyrIB
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