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)); 9<Kc9Z
} lL]8~3b
for(int i=0;i<nEndPos.length-1;i++) &bw ``e&c
{ 9G)q U
nEndPos = nStartPos[i+1]; `|d&ta[{
} ?> SH`\
nEndPos[nEndPos.length-1] = nFileLength; .X(*mmH
} Ii4lwZnz
} mIUpAOC`"Z
&]euL:C
\5=fC9*G
//启动子线程 -4!i(^w[m/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q[T='!Z\
for(int i=0;i<nStartPos.length;i++) `Q~`Eq?@
{ y*fU_Il|!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `Z!NOC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "i3Q)$"S
nStartPos,nEndPos,i); FdVWj 5 $a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +5C*i@v
fileSplitterFetch.start(); )Og,VXEB
} KtY_m`DY4R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ecl$z6'c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IsjD-t
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \/ 8 V|E
nEndPos = " + nFileLength); DGllJ_/Z
// fileSplitterFetch[nPos.length-1].start(); w+Cs=!
|e#ea~/b
a}]zwV&
//等待子线程结束 $YCy,Ew
//int count = 0; I_/kJ#7vj
//是否结束while循环 3[E)/~-
boolean breakWhile = false; //\UthOT
&:ib>EB03=
|Lz:i+;
while(!bStop) \hcb~>=C
{ ;}=[( eqA
write_nPos(); Nq3q##Ut:
Utility.sleep(500); Ikbz3]F^V
breakWhile = true; C)Ez>~Z
?[K\X
USrg,A
for(int i=0;i<nStartPos.length;i++) QA3q9,C"
{ 3%$nRP X
if(!fileSplitterFetch.bDownOver) 0W1=9+c|X
{ 5lMm8<v
breakWhile = false; 2rK<UPIq
break; SKf[&eP,G
} _Xn[G>1
} ;v?!Pml2k
if(breakWhile) Y)=89s&t
break; E'J| p7
8}0O @ wq
jLEwFPz
//count++; Zg@NMT
//if(count>4) M6+_Mi.
// siteStop(); TLk=HGw
} u\-f\Z7
Jc:gNQCsP
tE: m& ;I
System.err.println("文件下载结束！"); %TA3o71
} fEl,jA
catch(Exception e){e.printStackTrace ();} 4Fr\=TX
} }FTyRHD|
`Al5(0Q
^dzg'6M
//获得文件长度 K8l|qe
public long getFileSize() p7A&r:qq#
{ .d;XLS~
int nFileLength = -1; \HzI*|*A
try{ fi2@`37PM
URL url = new URL(siteInfoBean.getSSiteURL()); n>Rt9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x@I(G "
httpConnection.setRequestProperty("User-Agent","NetFox"); U&D"fM8
_"PTO&E
}cL9`a9j
int responseCode=httpConnection.getResponseCode(); L##lXUl
if(responseCode>=400) .cQ<F4)!tu
{ l(T CF
processErrorCode(responseCode); Vc!;O9dP
return -2; //-2 represent access is error 'j)xryw
} 0.~Pzg
w6fVZY4
!6pOY*> j
String sHeader; FX FTf2*T
xsx @aF
z~/z>_y$nv
for(int i=1;;i++) pv=g)
{ 8/;q~:v
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OgiElA.
//Utility.log(in.readLine()); "b!EtlT9
sHeader=httpConnection.getHeaderFieldKey(i); !`k{Ga
if(sHeader!=null) T'cahkSw'O
{ T #&9|
if(sHeader.equals("Content-Length")) 1A4!zqT;
{ XF{ g~M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xz'pZ*Hr$v
break; ?Mg&e/^
} ()Z!u%j
} 1}C|Javkn
else /3!KfG
break; $T\z
} c]>s(/}T
} $#g1Mx{
catch(IOException e){e.printStackTrace ();} d7y`AS@q6
catch(Exception e){e.printStackTrace ();} Zu\(XN?62
X=Q)R1~6v
:!M/9D*}0
Utility.log(nFileLength); #ra~Yb-F
VfJYYR
vs/.'yD/C
return nFileLength; )v-sde\
} +-=w`
+zQ a"Ep*
X ?/C9
//保存下载信息（文件指针位置） h&+dIk\[3
private void write_nPos() Ji_3*(
{ 3[E3]]OVa
try{ bu[v[U4
output = new DataOutputStream(new FileOutputStream(tmpFile)); kzG mDi
output.writeInt(nStartPos.length); {$,e@nn
for(int i=0;i<nStartPos.length;i++) :A\8#]3
{ ~a:0Q{>a
// output.writeLong(nPos); 8. [TPiUn'
output.writeLong(fileSplitterFetch.nStartPos); 8,pnm
output.writeLong(fileSplitterFetch.nEndPos); hBf0kl
} Fu0 dYN
output.close(); NKD<VMcqw
} :?s~,G_*l
catch(IOException e){e.printStackTrace ();} M-3kF"
catch(Exception e){e.printStackTrace ();} QCFLi n+r
} `Nn=6[]
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NDW6UFd>1
//读取保存的下载信息（文件指针位置） #Jv|zf5Z
private void read_nPos() 6fhH)]0
{ 0Zp) DM
try{ Y]aVa2!Wb
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t@[&8j2B>
int nCount = input.readInt(); D.zEE-cGyb
nStartPos = new long[nCount]; Vv4w?K
nEndPos = new long[nCount]; k/A8|
for(int i=0;i<nStartPos.length;i++) 4k5X'&Q
{ a9C8Q l
nStartPos = input.readLong(); Ah,X?0+
nEndPos = input.readLong(); GsG.9nd
} !rzbm&@
input.close(); 79|=y7i#
} dd#=_xe
catch(IOException e){e.printStackTrace ();} \jDD=ew
catch(Exception e){e.printStackTrace ();} ufE;rcYE
} >NWrT^rk
yrOWC
M=$ qus
private void processErrorCode(int nErrorCode) zdFO&YHTw
{ ?El8:zt?|
System.err.println("Error Code : " + nErrorCode); VMPBM:kG
} ?IR]y-r
,U+y)w]ar
/EF0~iy
//停止文件下载 SFVOof#s
public void siteStop() 4.:2!Q
{ a>x3UVf_
bStop = true; u}ULb F
for(int i=0;i<nStartPos.length;i++) BbEWa
fileSplitterFetch.splitterStop(); kLa9'c0
n,hl6[OL7
sdF;H[
} T8( \:v
} YqhZndktX
//负责部分文件的抓取 ~u-DuOZ8
**FileSplitterFetch.java f8yE>qJP
*/ b(JQ>,hX
package NetFox; DPCB=2E
r(;sX
0Q?XU.v
import java.io.*; d[mmwgSR?I
import java.net.*; v?e@`;- <
F?#^wm5TZ
6-8,qk
public class FileSplitterFetch extends Thread { p4QQ5O$;
qdkhfm2(K
Bw _^"e8X
String sURL; //File URL 'B dZN
long nStartPos; //File Snippet Start Position &[u%ZL
long nEndPos; //File Snippet End Position U$+EUDFi3_
int nThreadID; //Thread's ID ~d]X@(G&
boolean bDownOver = false; //Downing is over b&[bfM<
boolean bStop = false; //Stop identical dU`kJ,=Z
FileAccessI fileAccessI = null; //File Access interface M0Y#=u.
+XV7W=
:.8@ xVH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Dv~W!T i
{ 0LEJnl
this.sURL = sURL; 84g$V}mp
this.nStartPos = nStart; \)KLm
this.nEndPos = nEnd; RCM;k;@8V
nThreadID = id; 'sb&xj`d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 O# n<`;W
} !C13E lf
ZfMDyS$.
MIa#\tJj
public void run() {k BHZ$/
{ j#:IG/)GL
while(nStartPos < nEndPos && !bStop) 7A6Qrfw
{ (QS4<J"
8t)5b.PS
.V~z6
try{ L=g(w$H
URL url = new URL(sURL); W:5uoO]=<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); UnTnc6Bo7W
httpConnection.setRequestProperty("User-Agent","NetFox"); @ sLb=vb
String sProperty = "bytes="+nStartPos+"-"; UAleGR`,
httpConnection.setRequestProperty("RANGE",sProperty); %gBulvg
Utility.log(sProperty); w[ )97d
e_U1}{=t
dsJMhB_41U
InputStream input = httpConnection.getInputStream(); :g&9v_}&K{
//logResponseHead(httpConnection); s{g^K#BoFi
R( 2,1f=d
vwF#;jj\
byte[] b = new byte[1024]; O_vCZW a3
int nRead; KHnq%#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tqok.h
{ f/"?(7F
nStartPos += fileAccessI.write(b,0,nRead); }Pi}? 41!
//if(nThreadID == 1) M N-j$-y}
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Sq<ds}o'8l
} ;og[q
c+dmA(JC
Z+p'3
Utility.log("Thread " + nThreadID + " is over!"); {Xr|L
bDownOver = true; "XKcbdr8-
//nPos = fileAccessI.write (b,0,nRead); $TU:iv1Fm
} Dx1f<A1
catch(Exception e){e.printStackTrace ();} =74yhPAW
} V LXU
} K/T4T\
dZ6\2ok+
py-5 :g}d
//打印回应的头信息 n1Ic[cM}
public void logResponseHead(HttpURLConnection con) #_(t46
{ @%"+;D
for(int i=1;;i++) 3lh^maQ]
{ L0^rw|Z%'
String header=con.getHeaderFieldKey(i); Nw3K@Ge
if(header!=null) [hhPkJf|f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ve3-GWT{C
Utility.log(header+" : "+con.getHeaderField(header)); tBB\^xq:
else `8x.Mv
break; D MzDV_
} 2)-V\:;js
} V1l9T_;f
K>a@AXC
bM@8[&ta
public void splitterStop() Ca]V%g(
{ Aq]*$s2\G
bStop = true; @Z+(J:Grm5
} mMt~4(5
Q[6<Y,}(pd
PR+L6DT_
} zWA~0l.2
l|jb}9(J
i3dV2^O
/* v)c[-:"z
**FileAccess.java ]ykMh
*//文件访问(定位，写) =w,cdU*
package NetFox; }LA7ku
import java.io.*; +$CO
#Y_v0.N
-|cB7P
public class FileAccessI implements Serializable{ <&CzM"\Em
26[.te9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 h.t2;O,b
RandomAccessFile oSavedFile; 35}]U=
long nPos; ZHN}:W/p
-~+Y0\%E
`mp3ORR;$
public FileAccessI() throws IOException Y I?4e7Z+
{ dN)@/R^E;
this("",0); :c/](M
} o0B3G
b%_[\((
+Rq7m]
public FileAccessI(String sName,long nPos) throws IOException <#ZDA/G(
{ \L5h&
oSavedFile = new RandomAccessFile(sName,"rw"); yv+DM`0
this.nPos = nPos; u.!<)VIJx
oSavedFile.seek(nPos); <8sy*A?0z
} 7nl
z$]HZ#aRE
6>e YG<y{
public synchronized int write(byte[] b,int nStart,int nLen) y&(R1Y75
{ JQO%-=t
int n = -1; s9.nU
try{ w=}R'O;k
oSavedFile.write(b,nStart,nLen); TM*<hC
n = nLen; yS"; q
} S!{Kn ;@
catch(IOException e) ptCAtEO72
{ rvwfQ'14
e.printStackTrace (); ;sZHE&+
} _ ATIV
KOP*\\1 J
bA*T1Db,t>
return n; !vwx0
} ZnXq+^Z4
RxrUnMF
R3!3TJ
} %>)&QZig/
9xZ?}S:d
1z5\>F
/* bR&<vrMmrA
**SiteInfoBean.java AOVoOd+6
*/ TkjPa};R
package NetFox; K26x,m]p
$"`9QD~
vo3[)BDbT
public class SiteInfoBean { >x6$F*:W}
-mPrmapb3
iT}L9\
private String sSiteURL; //Site's URL $KGpcl
private String sFilePath; //Saved File's Path V9r58hbVT
private String sFileName; //Saved File's Name l6uUS
private int nSplitter; //Count of Splited Downloading File J`@#yHL
u,Rhm-`
~hxo_&
public SiteInfoBean() M!E#T-)
{//nSplitter的缺省值为5 }5qjGD
//default value of nSplitter is 5 %G>|u/:U
this("","","",5); c-, 6k
} xB&6f")
A1u|L^
{cF>,T
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) c(y~,hN&p
{ afWEt -
sSiteURL= sURL; FeM,$&G:
sFilePath = sPath; 3ZKaqwK
sFileName = sName; FII>6c
this.nSplitter = nSpiltter; 0XNj!^&
e2xqKG
I$7TnMug
} =*u:@T=d5
x# &ZGFr~
>&kb|)
public String getSSiteURL() LpJ_HU7@lk
{ |UO&18Y7-
return sSiteURL; }M I9?\"q
} s3LR6Z7;i
vs)1Rm
}813.U
public void setSSiteURL(String value) D(]])4
{ N>A*N,+
sSiteURL = value; A-dL_3
} H#joc0?P
FSvtiNW<
I@f">&^
public String getSFilePath() Cl+TjmOV\`
{ #VwA?$4g`
return sFilePath; ?+bDFM}
} [-bT_X
vKX $Nf
wPl!}HNf
public void setSFilePath(String value) o5N];Nj
{ 8;YN`S!o
sFilePath = value; vkXdKL(q
} Va1 eG]jQ
&dV|~xA6N
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public String getSFileName() I2!0,1Q
{ Yz?1]<X
return sFileName; 1/bu}?a
} mYudUn4Wo
k_=~ObA$g
BlVk?n
public void setSFileName(String value) g]g2`ab |
{ (zFUC]
sFileName = value; V+()`>44
} oj7X9~ nd
_`JYA
<h/\)bPB
public int getNSplitter() oK GFDl]3
{ p,=:Ff}~
return nSplitter; "}bk *2
} $o"PQ!z
C_[V[k0(
lxRzyx
public void setNSplitter(int nCount) FRicHs n
{ fWR]L47n
nSplitter = nCount; #_+T@|r
} R0y@#}JH
} 0 mWfR8h0
] =jnt
3:rH1vG.m
/* j/bebR}X
**Utility.java 1:%m >4U
*/ c 25wm\\
package NetFox; X,/@#pSOz
xw5E!]~D
&Z+a (
public class Utility { )>ed6A1
[|2uu."$
E(M\U5o:
public Utility() [H#I:d-+\
{ xa#:oKF3
5hE8b {V
U/M(4H3>H
} x7J|
rbnu:+!
//线程睡眠 UcMe("U
public static void sleep(int nSecond) C"/]X
{ N1I1!!$K;%
try{ HnVUG4yZTD
Thread.sleep(nSecond); EjB<`yT
} n%Xw6qV:
catch(Exception e) =VlO53Hy{
{ 4];Qpln
e.printStackTrace (); x#e(&OjN7
} Nh41o0
} #3$U&|`
E~zLhJTUL'
//日志 IPcAE!h6zN
public static void log(String sMsg) k6~k
{ :&`Yz
System.err.println(sMsg); c3|;'s
} yov:JnWo
~Gc+naE>
fPHv|_XM>
public static void log(int sMsg) sm}v0V.Js
{ M6!kn~
System.err.println(sMsg); ~aH*ZA*f
} 5/mW:G,&
} "HVwm>qEi
DRi!WWivn
muo7KUT
/* 1uv"5`%s
**TestMethod.java hE!3kaS
*/ doXd6q4H
package NetFox; "Q+'lA[}
2s EdN$O
Xt'R@"H<V9
public class TestMethod { L]#J?lE&
Ydmz!CEu
oC U8;z
public TestMethod() w"-bO ~5h
{ ///xx/weblogic60b2_win.exe V/|Ln*rm
try{ t9m:E
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )G ,LG0"-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z8kO*LYv
SiteFileFetch fileFetch = new SiteFileFetch(bean); `R8~H7{I6
fileFetch.start(); ~MO'%'@
} 9XS+W w7
catch(Exception e){e.printStackTrace ();} vsoj] R$C
[_qBp:_j?s
I~"-
} \,JRNL&
/Os)4yH\
sXl7
public static void main(String[] args) 8pDJz_F!{
{ .Rc&EO
new TestMethod(); [O [N_z
} d[rxmEXht
} nH% /
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