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)); .\_):j*
} wra0bS)4
for(int i=0;i<nEndPos.length-1;i++) k4Q>J,k
{ Gz&}OO
nEndPos = nStartPos[i+1]; O)jD2X?
} 1Uup.(
nEndPos[nEndPos.length-1] = nFileLength; ]i {yJ)i
} Kq[4I[+R
} I>?oVY6M@u
|]-Zz7N)
AM+5_'S,
//启动子线程 kQkc+sGJf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 36.,:!%p
for(int i=0;i<nStartPos.length;i++) @gN"Q\;F
{ O2fq9%lk
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !hVbx#bXl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), oC`F1!SfOO
nStartPos,nEndPos,i); :M(uP e=D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sp>g77@
fileSplitterFetch.start(); !E$$FvL
} n])#<0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wt/;iq"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2E }vuw=c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", z~Q=OPCnY
nEndPos = " + nFileLength); aL1%BGlmZ<
// fileSplitterFetch[nPos.length-1].start(); - lX4;
z&;8pZr
exq5Zc%
//等待子线程结束 L-+g`
//int count = 0; 6R45+<.
//是否结束while循环 T'pL&@,Q
boolean breakWhile = false; m-t:'B
)Qb,zS6
i~h@}0WR"
while(!bStop) #*bmwb*i
{ y#'hOSR2
write_nPos(); yzN[%/
Utility.sleep(500); 1AAyzAP9`
breakWhile = true; i#-v4g
\Th<7WbR6#
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for(int i=0;i<nStartPos.length;i++) `,]Bs*~
{ 8>YF}\D V
if(!fileSplitterFetch.bDownOver) 1<ag=D`F_"
{ )- W1Wtom
breakWhile = false; zT>!xGTu7~
break; 6*i**
} ET.jjV
} c)#P}Ai
if(breakWhile) l5-[a
break; !<M eWo
)JzY%a SP
?=&; A
//count++; oPi>]#X
//if(count>4) 2 GRI<M
// siteStop(); Ay(p~U;gN*
} CM?:\$4
n^nE&'[?0g
x3ZF6)@
System.err.println("文件下载结束！"); B@F@,?K4%
} v@$N,g
catch(Exception e){e.printStackTrace ();} 9JFN8Gf*)
} !AwMD
uG\~Hxqw7O
~ *&\5rPb
//获得文件长度 y?OP- 27y
public long getFileSize() %mC@}
{ ny{C,1QG
int nFileLength = -1; Om*QN]lGq
try{ CY o m
URL url = new URL(siteInfoBean.getSSiteURL()); ILm+o$o~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '?C6P5fm
httpConnection.setRequestProperty("User-Agent","NetFox"); yX!u&
I/7!5Z*
t^'nh 1=
int responseCode=httpConnection.getResponseCode(); F'XQoZ* 1
if(responseCode>=400) M">v4f&K1!
{ jz8u'y[n7
processErrorCode(responseCode); &3SS.&g4W
return -2; //-2 represent access is error \\SQACN
} 1gHe$dzXk
c~hH 7/v
]c>@RXY'
String sHeader; m[}P
D;YfQQr
P}4&J ^
for(int i=1;;i++) .HZd.*
{ h,{Q%sqO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); | In{5Ek
//Utility.log(in.readLine()); l\Ozy
sHeader=httpConnection.getHeaderFieldKey(i); ( eKgc
if(sHeader!=null) aMI;;iL^
{ +RJ{)Nec
if(sHeader.equals("Content-Length")) 0%bCP/
{ NQqw|3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); l>\EkUT
break; ^BF}wQb:j
} [-\Y?3
} ]r;rAOWVV
else wlNL;W@w
break; lgews"
} WX4sTxJK
} kgo#JY-4
catch(IOException e){e.printStackTrace ();} >SXSrXyYX
catch(Exception e){e.printStackTrace ();} k>ErDv8
_9>,9aL
Hf('BagBL
Utility.log(nFileLength); SRfh{u
[~N;d9H+*1
=RWTjTZ
return nFileLength; q=t!COS
} -jJhiaJ$<
CA#g(SiZ
^t'mW;C$4
//保存下载信息（文件指针位置） eJoM4v
private void write_nPos() h8(#\E
{ eKr>>4,-P
try{ [+o{0o>
output = new DataOutputStream(new FileOutputStream(tmpFile)); D|OGlP
output.writeInt(nStartPos.length); WRZpu95v
for(int i=0;i<nStartPos.length;i++) }sxs-
{ +Q+O$-a<
// output.writeLong(nPos); 6Rfv3
output.writeLong(fileSplitterFetch.nStartPos); !` 1h *}
output.writeLong(fileSplitterFetch.nEndPos); eV"%(<{
} i\CA6I
output.close(); 7RT{RE
} wm@j(h4
catch(IOException e){e.printStackTrace ();} B?%u<F
catch(Exception e){e.printStackTrace ();} lfAy$qP"}
} $$ND]qM$M
Iynks,ikA
2BC!,e$Z
//读取保存的下载信息（文件指针位置） 1NP
private void read_nPos() _\>y[e["p
{ 2mEqfy
try{ x/<ow4C
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); mW{;$@PLF"
int nCount = input.readInt(); GXZ="3W |
nStartPos = new long[nCount]; Qm[((6}
nEndPos = new long[nCount]; i$y=tJehi
for(int i=0;i<nStartPos.length;i++) QD.5oS
{ =OK#5r[UV
nStartPos = input.readLong(); k5< n:dS
nEndPos = input.readLong(); _YX% M|#
} 04U|Frc
input.close(); }tt%J[
} 1 fcV&qHR
catch(IOException e){e.printStackTrace ();} FJ84'T\~
catch(Exception e){e.printStackTrace ();} bbjba36RO
} $tu
^X&`YXjuN
|va@&;#wf
private void processErrorCode(int nErrorCode) 6 :4GI
{ ;Pk"mC
System.err.println("Error Code : " + nErrorCode); OD'~t,St
} :kHk'.V1(
lH3.q4D 5
-=lm`X<:
//停止文件下载 /6rjGc
public void siteStop() Mg\588cI
{ .Vt|;P}
bStop = true; K21Xx`XK
for(int i=0;i<nStartPos.length;i++) (m1m}* @
fileSplitterFetch.splitterStop(); wA{)9.
W^elzN(
1tXc7NA<
} d*+}_EV)Y3
} "dCIg{j
//负责部分文件的抓取 %# uw8V
**FileSplitterFetch.java Wqv7
*/ t'F$/mx.
package NetFox; q<\r}1Dm
+_:p8, 5o
r5&c!b\
import java.io.*; ScJ:F-@>
import java.net.*; xd3mAf
IG0_
!$HuH6_[
public class FileSplitterFetch extends Thread { X)SUFhP\
pW ~;B*hF
87[o^)8
String sURL; //File URL Oi?Q^ISxP
long nStartPos; //File Snippet Start Position 3R/6/+S-
long nEndPos; //File Snippet End Position ;7Qem&
int nThreadID; //Thread's ID xFUD9TM
boolean bDownOver = false; //Downing is over u&p8S#e
boolean bStop = false; //Stop identical ^I/(9KP#
FileAccessI fileAccessI = null; //File Access interface "a(R>PV%
^Whc<>|
g{DOQA
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =pe O%
{ 9I 6^-m@:
this.sURL = sURL; Yaq0mef0
this.nStartPos = nStart; ,dba:D=l
this.nEndPos = nEnd; 3Dc^lfn
nThreadID = id; 'q9Ejig
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -T+yS BO_3
} -6 v?iiZr
Ew}GPJ
7# 'j>]
public void run() Rt%Dps%
{ _BG`!3U+
while(nStartPos < nEndPos && !bStop) *QW.#y>"j
{ 9^SrOW6~
fo}@B&=4
7TAoWD3
try{ 3sBWtz
URL url = new URL(sURL); w;VUP@Wm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lItr*,A]
httpConnection.setRequestProperty("User-Agent","NetFox"); a[^dK-
String sProperty = "bytes="+nStartPos+"-"; Ahd{f!
httpConnection.setRequestProperty("RANGE",sProperty); yPbOiA*lHz
Utility.log(sProperty); K~L"A]+
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dkEnc
InputStream input = httpConnection.getInputStream(); y^p%/p%
//logResponseHead(httpConnection); YVY(uq)d
\@2sI
,v| vgt
byte[] b = new byte[1024]; g2 V $
int nRead; 'U`I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /-pop]L
{ ,Ur~DXY
nStartPos += fileAccessI.write(b,0,nRead); BcGQpv&x
//if(nThreadID == 1) >|T?87
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .>zkS*oX4z
} J! eVw\6
Q!%CU8!`&
a-TsD}'X
Utility.log("Thread " + nThreadID + " is over!"); I|[aa$G
bDownOver = true; ZoC?9=k
//nPos = fileAccessI.write (b,0,nRead); D+_PyK~jc
} EZiGi[t7
catch(Exception e){e.printStackTrace ();} "=!QSb
} PZA;10z
} &9] [~$
OEGAwP?F
{_MU0=7c\
//打印回应的头信息 !"J*
public void logResponseHead(HttpURLConnection con) zck |jhJ6
{ !r!Mq~X<=
for(int i=1;;i++) R}+/jh2O|
{ J&:0ytG
String header=con.getHeaderFieldKey(i); v:T` D
if(header!=null) &FvNz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $X&OGTlw^
Utility.log(header+" : "+con.getHeaderField(header)); E[Io8|QA
else \&qVr1|
break; 0Rk'sEX,
} 3S2'JOTY
} N$,)vb<
UZX)1?U
u!`C:C'
public void splitterStop() ze\~-0ks+
{ K;xW/7?
bStop = true; ti#sh{t
} rqh,BkQ0t
D\l.?<C
h'fD3Gr&
} ~D=@4(f8|
dO//
yEqmB4^-
/* yaR;
**FileAccess.java V=*J9~K
*//文件访问(定位，写) }Voh5*$E`
package NetFox; <d5vVn
import java.io.*; qRGb3l
Qy/bzO
;VFr5.*x
public class FileAccessI implements Serializable{ B:r-')!0$#
"=n8PNV/ c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;Gs**BB&
RandomAccessFile oSavedFile; C;) xjZiR
long nPos; _~(Xd@c(
:{ T#M$T
3ElpS^2W
public FileAccessI() throws IOException l=]vC +mU
{ XZ&v3ul
this("",0); Yr=mLT|JN
} S7q&|nI
"qm>z@K
Xbtv}g<0c
public FileAccessI(String sName,long nPos) throws IOException (}}8DB
{ RZtL<2.@
oSavedFile = new RandomAccessFile(sName,"rw"); uY~A0I5Z
this.nPos = nPos; ck~xj0
oSavedFile.seek(nPos); c-=0l)&'D=
} ^Q,/C8qeb
~+C#c,Nw
uRy6~'
public synchronized int write(byte[] b,int nStart,int nLen) |)-:w?
{ h^*{chm]
int n = -1; V$%K=[
try{ -N(MEzAE
oSavedFile.write(b,nStart,nLen); ">9CN$]J
n = nLen; y4L9Cxvs
} NFc8"7Mz}
catch(IOException e) ksaC[G;}:
{ A,e^bM
e.printStackTrace (); _MEv*Q@o
} %S#"pKE6R
L>b,}w
"y0A<-~
return n; 9.=#4OH/
} \IfgL$+
dSZ#,Ea"
5w1[KO#K|
} X8x>oV;8
7$=@q|$
+3>4 ?,^g
/* ;LE @Ezx
**SiteInfoBean.java fdG.=7`
*/ 3T/j5m}+!
package NetFox; $\!;*SSj
?63JQ.;
uP]o39b;V
public class SiteInfoBean { rfi`Bp
FO=1P7
m_ m@>}ud
private String sSiteURL; //Site's URL ;/T-rVND
private String sFilePath; //Saved File's Path \AzcW;03g[
private String sFileName; //Saved File's Name <R>ZG"m{
private int nSplitter; //Count of Splited Downloading File _[o^23Hj
K:@=W1
I}IW!K
public SiteInfoBean() 2QRn c"
{//nSplitter的缺省值为5 |=T<WU1$
//default value of nSplitter is 5 q*nz4QTOE
this("","","",5); W@dY:N}
} UJ$:5*S=u
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p&mtKLv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G9inNz*Cx
{ yWtr,
sSiteURL= sURL; u(Sz$eV
sFilePath = sPath; a?~csP^?}
sFileName = sName; c.Z4f7
this.nSplitter = nSpiltter; S\;.nAR
-$t,}3
am+mXb
} ha! "BR
9/(c cj
D#1~]d
public String getSSiteURL() 1T,PC?vr{
{ by[i"!RCu
return sSiteURL; i%4k5[f.:
} i(iP}:3
?(8%SPRk
y?#J`o- O
public void setSSiteURL(String value) B!ibE<7,
{ g+)\/n|
sSiteURL = value; yKEFne8^
} ,D2_Z]
gCr|e}w-
L_K\i?
public String getSFilePath() lY*]&8/=
{ O:tX0<6
return sFilePath; /.YAFH|i)"
} :yjK*"T|OD
ZCFf@2&z8
eSNSnh]'
public void setSFilePath(String value) xcvr D
{ '#PqI)P
sFilePath = value; wKS-O%?
} gam#6 s
%`1CE\f
lN>C#e<]
public String getSFileName() `Uj?PcS_
{ ##FNq#F
return sFileName; yPh2P5}H>
} Ca@=s
QsJW"4d
'F"Y?y:!
public void setSFileName(String value) RrdtU7i3
{ L"!ZY
sFileName = value; ~!:Sp_y
} JOx,19r
t{8v(}
6y,P4O*q
public int getNSplitter() =Z .V+4+
{ ,,gLrVk
return nSplitter; uV}WSoq[
} ViwpyC'v
Z<|_+7T
R=9~*9
public void setNSplitter(int nCount) O0wCb
{ tK|9qs<%
nSplitter = nCount; k)usUP'
} "G9'm
} _p J_V>l
.d~]e2x
cP@F #!2
/* ezr\T
**Utility.java FL#g9U>
*/ nz(q)"A
package NetFox; IFrb}yH
Go\} A:|s
$TA6S+
public class Utility { p37zz4
I51oG:6fR?
w~$c= JO#
public Utility() y^!E "
{ ?VZ11?u
r!.+XrYg
uojh%@.4
} 8{G?92 {rN
Z[k#AgC)
//线程睡眠 S0N2rU
public static void sleep(int nSecond) T1(j l)
{ (~ ]g,*+
try{ P^8^1-b
Thread.sleep(nSecond); &gA6+b'
} "B9[cDM&
catch(Exception e) 1c)\
{ Z#4JA/c!
e.printStackTrace (); `y^zM/Ib
} !f\?c7
} KbwTj*k[
>P\h,1
//日志 E[jXUOu-
public static void log(String sMsg) -}Cc"qm
{ Jt2,LL:G
System.err.println(sMsg); 8ji^d1G,
} O->_/_
|;A9A's
mW~i c
public static void log(int sMsg) a[1sA12
{ _{6,.TN
System.err.println(sMsg); ,8c dXt
} Jo{zy
} b:P\=k]8#
y$IaXr5L
E tJ~dL)
/* xClRO,-
**TestMethod.java n$.1Wk"
*/ mi7sBA9L8
package NetFox; e7@li<3>d
%{R_^Y8t
|x &Z~y
public class TestMethod { 3<c*v/L{C\
?^LG hdR
YF}9k
public TestMethod() 8#+`9GI
{ ///xx/weblogic60b2_win.exe a(8>n Z,V
try{ $brKl8P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `[WyHO|8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j#N(1}r=1
SiteFileFetch fileFetch = new SiteFileFetch(bean); }*iAE>;
fileFetch.start(); 89zuL18V
} &&X$d!V
catch(Exception e){e.printStackTrace ();} bt;lq!g
fd4;mc1T
@&?a]>L
} W|;nJs:e
C@%iQ]=
jEUx q%BH
public static void main(String[] args) B-!guf rnY
{ 8NnhT E
new TestMethod(); z>6.[Z(T
} xM&EL>m>L
} u\`/Nhn
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