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)); @MS;qoc
} V`=#j[gX)=
for(int i=0;i<nEndPos.length-1;i++) 6I"Q9(
{ |lrLTI^a
nEndPos = nStartPos[i+1]; $s$z"<
} Y;4nIWe JL
nEndPos[nEndPos.length-1] = nFileLength; fHdPav f,S
} )EcE{!H6+
} 8" XbW7^o
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ul1#_xp
//启动子线程 ng^`s}?o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Z[s{
for(int i=0;i<nStartPos.length;i++) Y]Td+Zi
{ +2!F6"hP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~bhesWk8!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XTyJ*`>
nStartPos,nEndPos,i); }hv>LL
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 22)2olU
fileSplitterFetch.start(); s`U.h^V
} q0,Diouq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7'k+/rAO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); T]Pp\6ff
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ORD@+ {
nEndPos = " + nFileLength); +h.$<=
// fileSplitterFetch[nPos.length-1].start(); )=8MO-{
I6ffp!^}Y
a39Kl_\
//等待子线程结束 "WV]| TS"]
//int count = 0; 615, P/
//是否结束while循环 |9$K'+'
boolean breakWhile = false; )<nr;n
LzEs_B=9
nJ<h}*[
while(!bStop) Yh\} i
{ dq?{?~3
write_nPos(); T.]+T[}!
Utility.sleep(500); x|&A^hQ
breakWhile = true; <E[X-S%&
s~W:N.}*
s>~ h<B
for(int i=0;i<nStartPos.length;i++) +}@1X&v:
{ yS%IE>?
if(!fileSplitterFetch.bDownOver) BrcT`MM[(=
{ I"eXoqh
breakWhile = false; Ze[ezu
break; (sSMH6iCif
} GSj04-T"
} sN.h>bd
if(breakWhile) S7vT=
break; df;-E
u2,V34b-
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//count++; }%Dsy2:y
//if(count>4) BuII|j
// siteStop(); Nz %{T
} |}P4Gr}6
`'H"|WsT
$$_aHkI j
System.err.println("文件下载结束！"); K6d9[;F
} ?]+{2&&$
catch(Exception e){e.printStackTrace ();} v0&E!4q*'
} O:3LA-vA
~OO&%\$k
[R:\
//获得文件长度 {L^b['h@
public long getFileSize() K"B2 SsC
{ #&a-m,Y$sx
int nFileLength = -1; 9&a&O Z{
try{ |7KW'=O
URL url = new URL(siteInfoBean.getSSiteURL()); PZmg7N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /2Q@M>
httpConnection.setRequestProperty("User-Agent","NetFox"); Vw0cf;
u?6L.^Op
J-yj&2
int responseCode=httpConnection.getResponseCode(); {U/a h2*
if(responseCode>=400) 0 UdAF
{ # Un>g4>Rh
processErrorCode(responseCode); :I*G tq
return -2; //-2 represent access is error |d =1|C%,
} o\6A]T=R
*Y(v!x \L
uH1%diL^
String sHeader; X~wkqI#d%E
JsAl;w
hqOy*!8'@
for(int i=1;;i++) w],+lN;
{ %v 0 I;t
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); {YnR]|0&
//Utility.log(in.readLine()); =g|e-XC
sHeader=httpConnection.getHeaderFieldKey(i); p(dJf&D
if(sHeader!=null) |eH>55 b
{ e%.Xya#\
if(sHeader.equals("Content-Length")) IO3`/R-
{ NGZEUtj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #'m&<g,
break; } m5AO4:
} k1Cx~Q)XC
} ernZfd{H
else ')ZxWYT O^
break; v|r\kr k
} (s`oJLW>
} r,F~Vwa}
catch(IOException e){e.printStackTrace ();} yM}b
catch(Exception e){e.printStackTrace ();} R(_UR)G0 @
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ZuF"GNUC
Utility.log(nFileLength); J?4aSssE
Ws2SD6!4`
V}<Hx3!
return nFileLength; P>q"P1&{
} "";[U
W+N9~.q\^
#lDf8G|ST~
//保存下载信息（文件指针位置） "o"ujQ(v
private void write_nPos() 4wfT8CL
{ TTB1}j+V6
try{ a|aRUxa0"
output = new DataOutputStream(new FileOutputStream(tmpFile)); H{}0-0o
output.writeInt(nStartPos.length); f`Km ctI
for(int i=0;i<nStartPos.length;i++) lFvRXV^+f
{ :6R0=oz
// output.writeLong(nPos); mY[s2t
output.writeLong(fileSplitterFetch.nStartPos); g+shz{3zvz
output.writeLong(fileSplitterFetch.nEndPos); ACQbw)tiv}
} OT-!n
output.close(); `@.
} 29eg.E
catch(IOException e){e.printStackTrace ();} |KSd@
catch(Exception e){e.printStackTrace ();} Fh t$7V
} 4-lG{I_S:
8w,U[aJm
$x_6 .AOZ,
//读取保存的下载信息（文件指针位置） *]uo/g
private void read_nPos() ch2Qk8
{ H(f~B<7q
try{ .-Y3oWV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S<), ,(
int nCount = input.readInt(); FtBYPSGz
nStartPos = new long[nCount]; XP#j9CF#.
nEndPos = new long[nCount]; 7kDX_,i
for(int i=0;i<nStartPos.length;i++) dV+%x"[:
{ Cm)_xnv
nStartPos = input.readLong(); v.Fq.
nEndPos = input.readLong(); b'i-/l$
} s-^B)0T!
input.close(); 0Vu&UD
} 2de[ yz
catch(IOException e){e.printStackTrace ();} 3a#X:?
catch(Exception e){e.printStackTrace ();} q:Lw!'Zh
} N^i<A2'6S;
BN!N_r
)Rhy^<xH
private void processErrorCode(int nErrorCode) o)w8 ]H/
{ _3_d;j#G U
System.err.println("Error Code : " + nErrorCode); 4yLC
} Yr9>ATR
&=bWXNU.
j#KL"B_A
//停止文件下载 {O\>"2}m'f
public void siteStop() ?,Z[)5 ZN
{ t{)Z$)'
bStop = true; c;\}R#
for(int i=0;i<nStartPos.length;i++) N^,@s"g
fileSplitterFetch.splitterStop(); kz4d"bTb
Be?b| G!M
{P'TtlEp
} B+e$S%HV
} 'k|?M
//负责部分文件的抓取 3&*_5<t\X
**FileSplitterFetch.java "YIrqk
*/ \;"$Z9W
package NetFox; B(}u:[ b^S
i1ph{;C
KIt:ytFx
import java.io.*; dQhh,}
import java.net.*; UsT+o
?sF<L/P0 F
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public class FileSplitterFetch extends Thread { i21ybXA=Z
S;0,UgB1
e_Cns&
String sURL; //File URL HS1Gy/6'
long nStartPos; //File Snippet Start Position ` oBlv
long nEndPos; //File Snippet End Position "S$4pj`<
int nThreadID; //Thread's ID ?QzA;8H
boolean bDownOver = false; //Downing is over Z#8O)GK
boolean bStop = false; //Stop identical YyI4T/0s_
FileAccessI fileAccessI = null; //File Access interface ZY%]F,Y
,,*i!%Adw
>3R%GNw
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException XhF7%KR
{ V{51wnxT
this.sURL = sURL; lZpa)1.tiC
this.nStartPos = nStart; Ave{ `YD
this.nEndPos = nEnd; C[cNwvz
nThreadID = id; [Xy^M3
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Vf Jpiv1
} gHU/yi!T
Vwj^h
Qg dHIMY
public void run() '%!'1si
{ EH;w <LvT
while(nStartPos < nEndPos && !bStop) d,"?tip/SX
{ \Qp #utC0s
&<{=
YuO-a$BP
try{ }=kf52Am,}
URL url = new URL(sURL); SG6@Rn*^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D@[Mk"f
httpConnection.setRequestProperty("User-Agent","NetFox"); _O!)aD
String sProperty = "bytes="+nStartPos+"-"; xRZ9.Agv_
httpConnection.setRequestProperty("RANGE",sProperty); ]?<j]u0J
Utility.log(sProperty); .A;D-"!
Z,'#=K
,TuDG*YA
InputStream input = httpConnection.getInputStream(); nF0V`O\T
//logResponseHead(httpConnection); 3`9H
D;@*
eQBR*@x
byte[] b = new byte[1024]; I+ZK \?Rs
int nRead; XY(3!>/eQ[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5w:
{ -Fcg}\9
nStartPos += fileAccessI.write(b,0,nRead); Y6(I %hE`
//if(nThreadID == 1) a<CN2e_Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &@E{0ZD
} fJ!i%</V
d8 1u
x"kc:F
Utility.log("Thread " + nThreadID + " is over!"); uo`O$k<;
bDownOver = true; Mx,QgYSu
//nPos = fileAccessI.write (b,0,nRead); }t4?*:\
} fFG, ^;7-O
catch(Exception e){e.printStackTrace ();} Y..
} 'n>,+,&
} L4th 7#
Fv n:V\eb
oObm5e*Z
//打印回应的头信息 x,W)qv
public void logResponseHead(HttpURLConnection con) _I;+p eq
{ L,Jl# S
for(int i=1;;i++) /I2RU2|B
{ #bX~.jKW
String header=con.getHeaderFieldKey(i); TV$Pl[m
if(header!=null) (<?6X9F:N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); m>4jRr6sF
Utility.log(header+" : "+con.getHeaderField(header)); Y)@mL~){
else I>k>^
break; S1Q2<<[
} \79KU
} voRr9E*n
cP[3p:
b2OVg +3
public void splitterStop() }wmn v
{ 4_3O?IY
bStop = true; 2mVcT3
} x <^vJ1
iV X12
,#G>&
} K-Bf=7F,
J(*QtF
vJ*IUy
/* !,}W|(P)
**FileAccess.java Ux_tHyc/
*//文件访问(定位，写) :+;AXnDM~
package NetFox; l?CUd7P(a
import java.io.*; b>|3?G
bH}6N>Fp
+^% y&8e
public class FileAccessI implements Serializable{ ns_5|*'
!6_lD0
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 G_EU/p<Q
RandomAccessFile oSavedFile; ~.qzQ_O/
long nPos; H"PnX-fGN
a\an
1(C3;qlVD
public FileAccessI() throws IOException V"n0"\k,
{ I(fq4$
this("",0); 41luFtE9
} @DgJxY|
6Q]c]cCu
a`5ODW+
public FileAccessI(String sName,long nPos) throws IOException D`]Lm24_]
{ %OWLM
oSavedFile = new RandomAccessFile(sName,"rw"); k)D:lpxv
this.nPos = nPos; uLV@D r
oSavedFile.seek(nPos); ~@ZdO+n?
} jbQ2G|:Q
fu|N{$h%X
J%']t$AR
public synchronized int write(byte[] b,int nStart,int nLen) jRN*W2]V
{ 0raVC=[
int n = -1; UkrqHHpy
try{ ]_NN,m>z
oSavedFile.write(b,nStart,nLen); "oZ]/(
n = nLen; %FnaS u
} 55xv+|k
catch(IOException e) 4`@]jm
{ 82Fq}N <
e.printStackTrace (); K @3 yS8F
} 1aKYxjYM
*<*{gO?Q4
0'!v-`.
return n; m#SDB6l
} hQ&S*f&='
Dt,b\6
& f7{3BK
} [.DSY[!8U
(A2x
@xR7>-$0p
/* )e.Y"5My
**SiteInfoBean.java v)@EK6Nty
*/ frS1<+
package NetFox; <VV./W8e9
IuDg-M[
0T2h3,
public class SiteInfoBean { -o\$.Q3
%zE_Q
lcgT9m#
private String sSiteURL; //Site's URL c;_GZ}8
private String sFilePath; //Saved File's Path :+ksmyW
private String sFileName; //Saved File's Name Tj@}O:q7:
private int nSplitter; //Count of Splited Downloading File GF5WR e(E
!=C4=xv
dw,Nlf~*0
public SiteInfoBean() 2SU G/-P#
{//nSplitter的缺省值为5 Q\G8R^9j p
//default value of nSplitter is 5 Izq]nR
this("","","",5); BQWEC,*N
} !}wJ+R ^2
0S@O]k)
d;&'uiS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P_+S;(QQ~d
{ 24{!j[,q@
sSiteURL= sURL; f !t2a//
sFilePath = sPath; ty]JUvR@
sFileName = sName; \Ku=a{Ne
this.nSplitter = nSpiltter; hGi"=Oud2
MfUG@
xkR--/f
} "-xm+7
S/-[OA>N
TkhbnO g6
public String getSSiteURL() >T{9-_#P
{ Tz.!
return sSiteURL; )#[?pYd
} ]xQPSs_
,Iq+v
kvs^*X''Ep
public void setSSiteURL(String value) \&]M \
{ Db\.D/76
sSiteURL = value; NL&(/72V
} Hno@
N'R^S98x
~/1kCZB
public String getSFilePath() Z"#ysC
{ tr"iluwGc
return sFilePath; >XP]NY}Po[
} i'J.c4
[7B:{sH
$wU.GM$t~
public void setSFilePath(String value) c38RE,4U
{ & Sy0Of
sFilePath = value; +]H9:ARI
} A<^IG+Q,B7
/3:R{9S%
x<60=f[O2R
public String getSFileName() r/=v;4.W
{ !q~s-~d^
return sFileName; W"4E0!r
} {EbR =
STu!v5XY}-
~PaD _W#xP
public void setSFileName(String value) 'qQ 5K o
{ e/lfT?J\
sFileName = value; @& #df
} {U(-cdU{e`
r=4'6!
qdh;zAMx
public int getNSplitter() "L.)ML
{ .6SdSB^M
return nSplitter; 5%D:wS1
} h>= e<H?f
bW<_K9"
L?&+*|VxI
public void setNSplitter(int nCount) .Tt \U
{ x3T)/'(
nSplitter = nCount; ,eOOV@3C
} :bwdEni1P
} {g\Yy(r
sLK J<=0i
1B=vrGq
/* Da1BxbDeI
**Utility.java =[(1u|H9
*/ X;flA*6V
package NetFox; .g DWv
4][m!dsU
_z\oDd`'
public class Utility { @i&LKr8
B1c`(mHl
62rTGbDbx
public Utility() 2NAGXWE
{ aUSxy8%
!uLAW_~
}!\NdQs
} E4[ |=<
Xhtc0\0"(
//线程睡眠 *c7kB}/
public static void sleep(int nSecond) [&t3xC,
{ @=`Dw/13
try{ CCfuz&
Thread.sleep(nSecond); z*ZEw
} }$#e&&)n
catch(Exception e) G U~?S'{
{ {,.1KtrSN
e.printStackTrace (); ,)'!E^n
} pSkP8' ?
} im9 B=D
/XS6X
//日志 pBiC
public static void log(String sMsg) [J\5DctX;c
{ 9_JK.
System.err.println(sMsg); 'VFxg,
} ]Rohf WHX
[Ua4{3#
dKDtj:
public static void log(int sMsg) -liVYI2s
{ EAxg>}'1j
System.err.println(sMsg); ?H eC+=/Z
} SPOg'
} ~!meO;|W
+e<P7}ZQ
Fzh%#z0
/* 9vCn^G%B
**TestMethod.java w_@NT}
*/ VE4!=4
package NetFox; ,=B "%=S
'cy35M
WRZi^B8@
public class TestMethod { `GC7o DL
irqlU
J)A1`(x&T
public TestMethod() 'e02rqip{
{ ///xx/weblogic60b2_win.exe 78#je=MDg
try{ #6fp"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H&E c*MT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dm,7OQ
SiteFileFetch fileFetch = new SiteFileFetch(bean); | ctGxS9
fileFetch.start(); "p.MJxH
} .x$+R%5U
catch(Exception e){e.printStackTrace ();} J6Hw05%0=
rmUTl
5FtbZ1L
} zCL/^^#
[%YA42_`LD
yeKzI~
public static void main(String[] args) Un^QNd>
{ !jMa%;/
new TestMethod(); 8HX(1nNj}
} )+wBS3BC
} 4LtFv)i
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