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)); KxQMPtHstz
} &A~hM[-
for(int i=0;i<nEndPos.length-1;i++) c uHF^l
{ W;|%)D)y
nEndPos = nStartPos[i+1]; 4X5KrecNr
} j5rMY=|F
nEndPos[nEndPos.length-1] = nFileLength; ^SW0+O
} UHBMl>~z
} OOnhT
i-R}O6
DSK?7F$_oE
//启动子线程 i'[! 'HY
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2W}jbOy
for(int i=0;i<nStartPos.length;i++) R]4 h)"
{ #?'@?0<6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f(T`(pX0V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )C0d*T0i
nStartPos,nEndPos,i); I/go$@E"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >tm4Rg~y
fileSplitterFetch.start(); Av!xI
} okTqq=xd`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RM>A9nv$\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0KA@]!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,>Dpt<
nEndPos = " + nFileLength); b"w@am>&
// fileSplitterFetch[nPos.length-1].start(); mQ2=t%
P2)/!+`a
g1@rY0O
//等待子线程结束 u@t~*E5BpM
//int count = 0; "G@(Cb*+T
//是否结束while循环 ?0+N
boolean breakWhile = false; b(t8TR#-
~Gl5O`w(
2.'hr/.
while(!bStop) S2>$S^[U
{ _%(.OR
write_nPos(); LQV&;O4'
Utility.sleep(500); ?RS4oJz,5g
breakWhile = true; gyxC)br
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,s/laZ)V
for(int i=0;i<nStartPos.length;i++) $GYy[8{:V
{ YKzfI9Y
if(!fileSplitterFetch.bDownOver) *E+VcU
{ Y$s4 *)%
breakWhile = false; 2Sk"S/4}Z
break; ?} lqu7S
} G!lF5;Ad`
} plpb4> S
if(breakWhile) O`T_'.Lk
break; @WiTh'w0
]GD&EQ
zL9:e7o
//count++; 1fC)&4W
//if(count>4) POf xN.
// siteStop(); tJmy}.t1
} KNR7Igw?}
i*@ZIw
N%%trlDXD
System.err.println("文件下载结束！"); gw^W6v
} 8fktk?|
catch(Exception e){e.printStackTrace ();} 2#N?WlYw<S
} + WT?p]
u=Xpu,q
}aQ*1Vcj
//获得文件长度 4p%^?L?
public long getFileSize() Gte\=0Wr
{ Wevd6)\
int nFileLength = -1; _9q byhS7
try{ X*9-P9x(6
URL url = new URL(siteInfoBean.getSSiteURL()); "=LeHY=9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j8aH*K-l{
httpConnection.setRequestProperty("User-Agent","NetFox"); \:+ NVIN
~+V$0Q;L
q_98=fyE6
int responseCode=httpConnection.getResponseCode(); mF UsTb]f
if(responseCode>=400) RxNLn/?d@
{ <[u(il
processErrorCode(responseCode); ?cn`N|
return -2; //-2 represent access is error VTY #{
} J'tJY% `
v*c"SI=@M=
<PM.4B@
String sHeader; z?F`)}
J _q
T3LVn<Lm\
for(int i=1;;i++) 9+/D\|"{
{ 0d1!Q!PH3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @"wX#ot
//Utility.log(in.readLine()); <4~SFTWY
sHeader=httpConnection.getHeaderFieldKey(i); %LD(S*>7
if(sHeader!=null) EBiLe;=X
{ %oquHkX%OJ
if(sHeader.equals("Content-Length")) d_ x jW
{ )u4=k(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'St?nW3
break; ydj*Jy'
} d1D=R8P_u
} |o*qZ}6
else 6q!Q([D_
break; esq~Ehr=
} R&g&BF
} IO]tO[P#
catch(IOException e){e.printStackTrace ();} `^ a:1^
catch(Exception e){e.printStackTrace ();} 2aX$7E?
rixVIfVF
NeP
Utility.log(nFileLength); J<4_<.o(a
ynZEJKo
&9z&#`AY]>
return nFileLength; Z'l!/l!
} U<>@)0~7g!
ZS=;)
=sefT@<
//保存下载信息（文件指针位置） !ZvVj\{
private void write_nPos() %d40us8E
{ ^f-)gZ&
try{ 2I& dTxIa
output = new DataOutputStream(new FileOutputStream(tmpFile)); DY{v@ <3
output.writeInt(nStartPos.length); G)c+GoK
for(int i=0;i<nStartPos.length;i++) T 1_B0H2
{ G l2WbY
// output.writeLong(nPos); R0F [
output.writeLong(fileSplitterFetch.nStartPos); ,-8Xb+!8I
output.writeLong(fileSplitterFetch.nEndPos); y?A*$6
} b\zq,0%
output.close(); 2(Yg',aMY-
} ;' |CSjco
catch(IOException e){e.printStackTrace ();} >n(dyU@
catch(Exception e){e.printStackTrace ();} Sa0IRC<LV
} Xwjm T
V~Z)^.6
b?VByJl
//读取保存的下载信息（文件指针位置） 7/_|/4&
private void read_nPos() P}(c0/
{ a=x&sz\x
try{ dmcY]m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "%S-(ue:
int nCount = input.readInt(); VUP. \Vry
nStartPos = new long[nCount]; o|c&$)m
nEndPos = new long[nCount]; Qh6vH9(D
for(int i=0;i<nStartPos.length;i++) "gzn%k[D9m
{ vu}U2 0@
nStartPos = input.readLong(); !0UfX{.
nEndPos = input.readLong(); 1zw,;m n
} tFX<"cAvK
input.close(); #3eI4KJ4+l
} E>gLUMG$
catch(IOException e){e.printStackTrace ();} A7&/3C6{H
catch(Exception e){e.printStackTrace ();} p!)tA
} "Mv^S'?>
q[}re2
2V$Jn8v,`{
private void processErrorCode(int nErrorCode) lUp%1x+
{ .sOZ"=tW
System.err.println("Error Code : " + nErrorCode); vpOGyvI
} g 4|ai*^
ygX!'evY
,,6lQ]wG
//停止文件下载 ;-l^X%r
public void siteStop() Ux{QYjFE
{ heB![N0:
bStop = true; 2']0c z
for(int i=0;i<nStartPos.length;i++) qu]a+cYY
fileSplitterFetch.splitterStop(); "*V'
R/Sm
[u J<]
} [D(JEO@ :
} )56L`5#tS
//负责部分文件的抓取 gp~-n7'~O
**FileSplitterFetch.java O U9{Y9e
*/ | z_av
package NetFox; Ol<LL#<j4
=knLkbiq7,
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import java.io.*; nw_|W)JVQ
import java.net.*; $Fy~xMA8O
2`ERrh^i"
M9Yov4k,4]
public class FileSplitterFetch extends Thread { aHI~@
NS+uiy
-em3 #V
String sURL; //File URL q$IU!I4
long nStartPos; //File Snippet Start Position M195[]
long nEndPos; //File Snippet End Position TaKHr$h
int nThreadID; //Thread's ID .L^;aL
boolean bDownOver = false; //Downing is over eI|~neh
boolean bStop = false; //Stop identical YnDaBpx
FileAccessI fileAccessI = null; //File Access interface MrOtsX
^L Xr4
W~i0.rg|>
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eecIF0hp
{ vl|3WYA
this.sURL = sURL; z~v-8aw
this.nStartPos = nStart; k<f0moxs'
this.nEndPos = nEnd; e%{7CR'~TD
nThreadID = id; @T.F/Pjhc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8JW0;H<
} zJ ;]z0O
'-G,7!.,r%
`Pwf?_2n-
public void run() 2)n%rvCQ
{ XuZgyt"=r
while(nStartPos < nEndPos && !bStop) >s,*=a
{ Pl#u,Y
L;b-=mF
(5[#?_~
try{ I/v#!`L
URL url = new URL(sURL); -(}N-yu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W&Xi&[Ux
httpConnection.setRequestProperty("User-Agent","NetFox"); 3=UufI
String sProperty = "bytes="+nStartPos+"-"; iU~d2R+
httpConnection.setRequestProperty("RANGE",sProperty); ,5K&f\
Utility.log(sProperty); 9jl\H6JY|
|c-`XC2g
C)9-{Yp
InputStream input = httpConnection.getInputStream(); gq~`!tW'
//logResponseHead(httpConnection); `$3P@SO"
|Xv\3r
XoMgbDC
byte[] b = new byte[1024]; *|0W3uy\Y
int nRead; Z vyF"4QN
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *0'{n*>
{ WFS6N.Ap
nStartPos += fileAccessI.write(b,0,nRead); %VXIiu[
//if(nThreadID == 1) ~wGjr7Wt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /\1Q :B3W
} MzlE
E!I4I'
.Dr7YquW
Utility.log("Thread " + nThreadID + " is over!"); v yP_qG
bDownOver = true; td#m>S
//nPos = fileAccessI.write (b,0,nRead); +yHzp
} +,D82V7S
catch(Exception e){e.printStackTrace ();} WCp[6g&%O
} PM {L}tEQ
} jd 8g0^
y92<(ziaX)
2fPMZ7Zd3
//打印回应的头信息 `0{qfms
public void logResponseHead(HttpURLConnection con) U?(,Z$:N
{ p4b6TI9;
for(int i=1;;i++) :4COPUBpPV
{ \D[~54
String header=con.getHeaderFieldKey(i); sn@)L~$V
if(header!=null) g|!=@9[dv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); icK U)
Utility.log(header+" : "+con.getHeaderField(header)); ?C6`
else \OK}DhY#
break; xlW>3'uHfa
} Me;Nn$'%
} lPlJL`e
}yCgd 5+_
i l%9j
public void splitterStop() _b=})**
{ x6=tS
bStop = true; /J,&G: Er
} ^$lsmF]^
o`}8ZtD
2TaHWw<A
} hrOp9|!m
2L1Azx
%';DBozZ
/* hDEZq>&
**FileAccess.java ]08~bL1Q
*//文件访问(定位，写) "xD5>(|^+Q
package NetFox; r1$x}I#Zv
import java.io.*; B_.>Q8tK;
"n<u(m8E
+Pn`AV1
public class FileAccessI implements Serializable{ Z,b^f Vw
a+\s0Qo<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HMR!XF&JjC
RandomAccessFile oSavedFile; 8ZO~=e
long nPos; Gv\fF;,R
nON"+c*
v/wR)9
public FileAccessI() throws IOException 061f
{ I,lzyxRP
this("",0); An !i
} NW Pd~l+
.GPuKP|
h3A|nd>\
public FileAccessI(String sName,long nPos) throws IOException j;*= ^s
{ aK9zw
oSavedFile = new RandomAccessFile(sName,"rw"); sY'dN_F
this.nPos = nPos; ;WL0
oSavedFile.seek(nPos); 5d82Ms
} f<3r;F7
0 f"M-x
#DHeEE
public synchronized int write(byte[] b,int nStart,int nLen) niM(0p
{ t]pJt
int n = -1; &44?k:
try{ ]^l-k@
oSavedFile.write(b,nStart,nLen); >Q^*h}IdW
n = nLen; \Ng[lN
} PFeK;`[
catch(IOException e) O,KlZf_B
{ dtq]_HvTJ
e.printStackTrace (); yAVt[+0
} vy F(k3W
UIw6~a3E
eYRm:KC
return n; eD 7Rv<
} Z?'){\$*
knZ<V%/e
1uhSP!b
} i'vjvc~
Q|cA8Fn
Ad`jV_z
/* 1Aa=&B2
**SiteInfoBean.java .DHRPel
*/ %AuS8'Uf
package NetFox; H=9\B}
GpM_Qp
#Y<b'7yJ
public class SiteInfoBean { b~FmX
aD3Q-a[
5($ '@u
private String sSiteURL; //Site's URL N DV_/BI
private String sFilePath; //Saved File's Path S>p>$m, Q
private String sFileName; //Saved File's Name rW3fd.;kss
private int nSplitter; //Count of Splited Downloading File /=7[Q
^zaN?0%S33
@;z}Hk0A
public SiteInfoBean() 'GcZxF0
{//nSplitter的缺省值为5 aG\B?pn-
//default value of nSplitter is 5 6e;.}i
this("","","",5); \<A@Nf"
} tI(co5 W
.{W)E
sWnU*Q
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YEqWTB|w
{ Bhrp"l +|
sSiteURL= sURL; :!Tb/1
sFilePath = sPath; v4Q8RE?
sFileName = sName; {z}OZHJN
this.nSplitter = nSpiltter; ) 4'@=q
/1lUFL2D
CR$5'#11)
} mWM!6"
ZK]C!8\2|
|bz,cvlP W
public String getSSiteURL() ]={{$}8.
{ bdCpGG9
return sSiteURL; etH%E aF[
} dGzZ_Vf
Oj0/[(D-
`W8dayZt
public void setSSiteURL(String value) g< {jgF
{ bXiT}5mJU
sSiteURL = value; j7 D\O
} zW^@\kB0D
NUH#
/P0%4aWu=
public String getSFilePath() H;$OCDRC
{ |ldRs'c{
return sFilePath; 6(}8[i:
} SpY%2Y.Dy
gI^*O@Q4{b
.gWYKZM
public void setSFilePath(String value) 5A6d]
{ >2~q{e
sFilePath = value; K_B-KK(^
} y8un&LP
x*[\$E`v
/wL}+
public String getSFileName() \6xVIQ& 0
{ v7/qJ9l
return sFileName; e? fFh,a
} ~V"D|U;i +
.~6p/fHX
DO$jX 4
public void setSFileName(String value) dg4 QA_"
{ g%Ap<iT
sFileName = value; (;'?56
} <gKT7ONtg
b^\u P
Hs8c%C
public int getNSplitter() |}\et ecB
{ ,!3G
return nSplitter; >T4.mB7+>
} :d-+Z%Y
ND7 gxt-B
A|8(3PiP
public void setNSplitter(int nCount) ^l6q
{ P-VK=Y1q
nSplitter = nCount; 969*mcq'
} _*+ 7*vAL
} %@5f+5{i!z
Qe=!'u.nL
`|;R}"R;
/* ;K0kQ<y-Y
**Utility.java wbzAX
*/ ucyz>TL0
package NetFox; FMuM:%&J]
{|6(_SM|
l=ZhHON
public class Utility { Dm[4`p@IY\
]w(i,iJ
A -G?@U
public Utility() >v`lsCGb
{ |b52JF ",
`Xnu("w)
v3Y/D1jd"
} m6)8L?B
9Bl_t}0
//线程睡眠 Im1e/F]
public static void sleep(int nSecond) [MYd15
{ eW]K~SPd7
try{ h\b]>q@
Thread.sleep(nSecond); B]q &?~
} ~&=-*
catch(Exception e) }N1Z7G
{ jx&pRjP
e.printStackTrace (); =)(o(bfSKr
} UfSWdR)
} j9sf~}D>
[: X
//日志 *BT-@V.4
public static void log(String sMsg) =usx' #rb
{ r"SuE:D
System.err.println(sMsg); 'c\zWmAZ
} JB a:))lw
C XZm/^
n0kBLn
public static void log(int sMsg) -82Rz
{ zo&'2I
System.err.println(sMsg); _H|x6X1-
} |<P]yn
} P'GX-H
TGGeTtk=
j8!fzJG
/* [L8Bgw1
**TestMethod.java _K>cB<+d
*/ K>9]I97g'
package NetFox; 7M<Ae D%
<XX\4[wb
q4PRc<\^
public class TestMethod { hVI $r
Y(ly0U}
r>sk@[4h
public TestMethod() @!&\Z[",
{ ///xx/weblogic60b2_win.exe \aQBzEX
try{ ]L%qfy4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Q2iS0#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0m6Vf x
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ps(3X@
fileFetch.start(); CE:TQzg
} B5aFt ;Vj
catch(Exception e){e.printStackTrace ();} 8'_>A5L/C
MOY.$M,1
sXkWs2!
} %p)6m2Sb
|j$&W;yC
IY?[0S
public static void main(String[] args) gR"'|c
{ bWo-( qxq
new TestMethod(); 2c@R!*
} 5bR;R{:x
} f@Rn&&-
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