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)); ;o^eC!:/%
} }E+!91't.^
for(int i=0;i<nEndPos.length-1;i++) ;,$NAejgd
{ O!zV)^r
nEndPos = nStartPos[i+1]; m`IC6*
} U1@IX4^2`
nEndPos[nEndPos.length-1] = nFileLength; IC#>X5
} IM:=@a{
} |M>eEE*F<
6BY-^"W5`
!(mjyr
//启动子线程 wAX1l*`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; O#x*iI%
for(int i=0;i<nStartPos.length;i++) 3 j!3E
{ }XZ'v_Ti
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iDN;m`a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m$`RcwO
nStartPos,nEndPos,i); 6Se?sHC>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fXXr+Mor
fileSplitterFetch.start(); *"R|4"uy
} 2Gz}T _e
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /|r^W\DV&x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =7-9[{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", e8y;.D[2
nEndPos = " + nFileLength); ~hZ"2$(0
// fileSplitterFetch[nPos.length-1].start(); d{rQzia"mV
A3rPt&<a
IN4=YrM^
//等待子线程结束 s4G|_==
//int count = 0; A:>01ZJ5S+
//是否结束while循环 cmBB[pk\
boolean breakWhile = false; ^:K3vC[h;c
unshH<
FjK3 .>'
while(!bStop) 0T@Zb={
{ [r3!\HI7x
write_nPos(); -d8TD*^
Utility.sleep(500); @_U;9)
breakWhile = true; ,^?^dB
|s)Rxq){"V
8 ![|F:
for(int i=0;i<nStartPos.length;i++) ,O.3&Nz,c
{ CJ(NgYC h
if(!fileSplitterFetch.bDownOver) '/`= R
{ eKgisY4#
breakWhile = false; 7bqBk,`9
break; 7]^M>#
} ;E@G`=0St
} pR `>b 3
if(breakWhile) 6Ca(U'
break; C2@,BCR
Ol1e/Wv
=6woWlfb
//count++; '=[?~0(B
//if(count>4) 4?0vso*X<:
// siteStop(); ">~.$Jp_4
} 7Ok;Lt!x
2}YOcnB
aJYgzr,
System.err.println("文件下载结束！"); z)'Mk[
} n_$ :7J
catch(Exception e){e.printStackTrace ();} el2bd :
} dOqOw M.y
Fp@TCPe#
6^uq?
//获得文件长度 {88)~
public long getFileSize() eyefWn&
{ NZ;{t\
int nFileLength = -1; '#s05hr
try{ 0.dgoq3u
URL url = new URL(siteInfoBean.getSSiteURL()); 5:O-tgig.
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }~#pEX~j*
httpConnection.setRequestProperty("User-Agent","NetFox"); xB_!>SqF1U
}MRd@ 0-?!
MHSs!^/g5
int responseCode=httpConnection.getResponseCode(); tYZ[68
if(responseCode>=400) }Mo=PWI1?
{ @|<<H3I
processErrorCode(responseCode); :{qv~&+C
return -2; //-2 represent access is error ~vs}.kb
} QF{4/y^j{
ld3-C55
-M%_\;"de
String sHeader; [`p=(/I&L
MxWy*|J}
WtViW=j'
for(int i=1;;i++) RMd[Yr2e
{ ?dD&p8{
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h]og*(
//Utility.log(in.readLine()); 4$qWiG~
sHeader=httpConnection.getHeaderFieldKey(i); ELBa}h;
if(sHeader!=null) ,z3{u162
{ b|cyjDMAA
if(sHeader.equals("Content-Length")) 20vXSYa~
{ ]d,S749(s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >2~+.WePu
break; io,M{Ib
} J\d3N7_d
} %FXfqF9
else ObLly%|i
break; I"Ms-zs
} (rkyWz
} O<96/a'
catch(IOException e){e.printStackTrace ();} RRmLd/(
catch(Exception e){e.printStackTrace ();} T?:glp[4I
ZN!4;
_u{c4U0,
Utility.log(nFileLength); QA2borfy
j{Hao\F8
oo.!.Kv
return nFileLength; _cy2z
} {z(xFrY
bA\<.d
YGv<VOWG2
//保存下载信息（文件指针位置） Yu?95qktP
private void write_nPos() <,3^|$c%
{ %6L^2 X
try{ b8LoIY*
output = new DataOutputStream(new FileOutputStream(tmpFile)); fQL"O}Z
output.writeInt(nStartPos.length); g0>,%b
for(int i=0;i<nStartPos.length;i++) e?_@aa9~@{
{ WA]c=4S
// output.writeLong(nPos); ]Tkc-ez
output.writeLong(fileSplitterFetch.nStartPos); N-I5X2
output.writeLong(fileSplitterFetch.nEndPos); :!5IW?2
} 5QPM t^
output.close(); Lg~B'd8m
} IB# @yH
catch(IOException e){e.printStackTrace ();} = QQ5f5\l
catch(Exception e){e.printStackTrace ();} Y^ kXSU
} vFE;D@bz:
ta`N8vnf
$-#Yl&?z9
//读取保存的下载信息（文件指针位置） 58%#DX34M
private void read_nPos() Q-MQ9'
{ X>NhZ5\
try{ 1WY/6[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Zm=(+ f
int nCount = input.readInt(); (>`5z(X
nStartPos = new long[nCount]; `)GrwfC
nEndPos = new long[nCount]; 2Yp7
for(int i=0;i<nStartPos.length;i++) {]E+~%Va
{ e&>;*$)
nStartPos = input.readLong(); )K,F]fc+O
nEndPos = input.readLong(); H2 $GIY
} %Eb%V($
input.close(); i/~1F_
} S}$r>[t
catch(IOException e){e.printStackTrace ();} ms!ref4`+
catch(Exception e){e.printStackTrace ();} e*bH0';q
} (T!9SU
BNd^qB ?
\e!vj.PU
private void processErrorCode(int nErrorCode) fO0(Z
{ F1jglH/MF)
System.err.println("Error Code : " + nErrorCode); +n<k)E@>J
} ]%BWIqbr
Nluv/?<
Pcu#lWC$
//停止文件下载 $aN-Y?U%
public void siteStop() N@Y ljz|
{ )RO<o O
bStop = true; ~4s'0 w^
for(int i=0;i<nStartPos.length;i++) KN tt
fileSplitterFetch.splitterStop(); cx}Q2S
$/=nU*pd
4m*M,#mV
} p98~&\QT
} $BFvF ,n
//负责部分文件的抓取 ?t+5s]
**FileSplitterFetch.java %]I ZLJ
*/ &^}6 9
package NetFox; |1ST=O7.LH
+)j1.X
h$.:Uj8/
import java.io.*; _)]+hUwY
import java.net.*; N\HQN0d9
tID%}Zv
&}?$i7x5
public class FileSplitterFetch extends Thread { ;5tazBy&:C
zo[[>MA
^|/](
String sURL; //File URL W?eu!wL#p
long nStartPos; //File Snippet Start Position }~"hC3w
long nEndPos; //File Snippet End Position x_c7R;C
int nThreadID; //Thread's ID ZTU&,1Y;
boolean bDownOver = false; //Downing is over rAs,X
boolean bStop = false; //Stop identical LJOr!rWi
FileAccessI fileAccessI = null; //File Access interface UTf9S>HS
#]#sGmW/L
"TUe%o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Kx=4~
{ :$_6SQ<?
this.sURL = sURL; H}H7lO
this.nStartPos = nStart; Nnk@h
this.nEndPos = nEnd; mcn 2Wt
nThreadID = id; ~BDu$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nPs7c %
} /F4pb]U!*
81hbk((
[74F6Qp
public void run() H(Q.a=&4!p
{ 7<jZ`qdq_
while(nStartPos < nEndPos && !bStop) Pfm_@'8
{ ^Ve<>b
esHQoIhd
0TmR/uUT
try{ 0H0-U'l
URL url = new URL(sURL); Gg~QAsks
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >[Ye
httpConnection.setRequestProperty("User-Agent","NetFox"); sf]s",t~J
String sProperty = "bytes="+nStartPos+"-"; \EKU*5\Hp>
httpConnection.setRequestProperty("RANGE",sProperty); CBDG./
Utility.log(sProperty); {5d9$v7k4
rQEyD
5w\fSY
InputStream input = httpConnection.getInputStream(); 52b*[tZ
//logResponseHead(httpConnection); NTS#sgP
k6Uc3O
u~3%bJ]
byte[] b = new byte[1024]; ]D@0|
int nRead; l#lF +Q;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &q`q4g&7
{ ,(.MmP`
nStartPos += fileAccessI.write(b,0,nRead); F[4;Xq
//if(nThreadID == 1) MB%Q WU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \~BDm
} f8SL3+v
Dk+&X-]6x5
f+|$&p%
Utility.log("Thread " + nThreadID + " is over!"); quvanxV-L
bDownOver = true; Up:<=Kgci
//nPos = fileAccessI.write (b,0,nRead); Gcb|W&
} H*bs31i{
catch(Exception e){e.printStackTrace ();} ALEnI@0
} ?d4m!HgR
} )@~J
yA)(*PFz
= pI?A^
//打印回应的头信息 TLd`1Ac
public void logResponseHead(HttpURLConnection con) P7 PB t
{ OiAJ[L
for(int i=1;;i++) =1P6Vk
{ hXb%;GL
String header=con.getHeaderFieldKey(i); Qfky_5R\
if(header!=null) T]j.=|,d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Wd0[%`dq
Utility.log(header+" : "+con.getHeaderField(header)); .<z!3O&L
else dgDy5{_
break; 8/t$d#xHI
} h'$QC )P
} rJa$9B*^
"+zCS|
sP-^~ pp
public void splitterStop() @]qBF]6
{ >Bs#Xb_B]
bStop = true; %lX%8Z$v
} k"g._|G
G[8in
49d@!
} K_ lVISBQ
`fNG$ODL
GZ{]0$9I'
/* ,+g&o^T
**FileAccess.java f50L,4,
*//文件访问(定位，写) $!5\E>y#
package NetFox; bWZbG{Y.
import java.io.*; W5^.-B,(K
~+<olss_
hLDA]s
public class FileAccessI implements Serializable{ Z4){ 7|~a
t8+_/BXv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zE)~0v4
RandomAccessFile oSavedFile; Fb/XC:AD
long nPos; hk/! 'd
6{,HiY
}<PxWZ`,\
public FileAccessI() throws IOException ?:|-Dq,
{ |v[Rp=?]
this("",0); Qu<Bu)`
} l88A=iLgv
kD) $2I?
}pa9%BQI
public FileAccessI(String sName,long nPos) throws IOException 4d_s%n?C
{ dq IlD!
oSavedFile = new RandomAccessFile(sName,"rw"); eZr&x~] -w
this.nPos = nPos; =<@\,xN>C
oSavedFile.seek(nPos); UZEI:k,dv
} -o+74=E8[?
=pA IvU
^E6d`2w-
public synchronized int write(byte[] b,int nStart,int nLen) 'a^{=+
{ pG^}Xf2a
int n = -1; >K# ,cxY
try{ =`Y.=RL+'n
oSavedFile.write(b,nStart,nLen); Y~)T
n = nLen; "xAWG$b
} :K?0e`
catch(IOException e) Z?J:$of*
{ y fSM
e.printStackTrace (); WZ!WxX>zO
} Qp2I[Ioz3
9_fePS|Z4
wh:1PP
return n; VR!-%H\AW
} 51#"3S
dY"}\v6
$|KaBx1
} ;NV'W]
L:M0pk{T
}j1!j&&
/* IMnP[WA!
**SiteInfoBean.java M[~{Vd
*/ _ nP;Fx
package NetFox; F8e<}v&7R
i#X!#vyc
^MD;"A<
public class SiteInfoBean { 8hA^`Y
>x3ug]Bu
Px M!U!t
private String sSiteURL; //Site's URL kl1Y] ?z}
private String sFilePath; //Saved File's Path E3a_8@ZB7
private String sFileName; //Saved File's Name WxbsD S;
private int nSplitter; //Count of Splited Downloading File 6|J'>)
vRA',(](
zH=!*[d8
public SiteInfoBean() qQ7w&9r.M
{//nSplitter的缺省值为5 1\dn1Hh
//default value of nSplitter is 5 4gdY`}8b^}
this("","","",5); ,pK|SL
} NHw x:-RH
gM>=%/.
4z:#I;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `ya;:$(6
{ SbsouGD,{
sSiteURL= sURL; 'mdMq=VI
sFilePath = sPath; oKFT?"[X
sFileName = sName; JO@Bf
this.nSplitter = nSpiltter; O`cu_
TO;.eN!sv
g^kx(p<u`
} !C:rb
Y{f7 f'_
92dF`sv
public String getSSiteURL() 3Dm8[o$Z
{ \'19BAm'
return sSiteURL; {+("C] b
} 4ZT A>
y?30_#[dN
L6 6-LMkH
public void setSSiteURL(String value) +TN9ujL6@
{ l{P\No
sSiteURL = value; __p_8P
} V'Qn sI
km:nE: |
H L<s@kEZ
public String getSFilePath() tn/T6C^)
{ <XQ.A3SG!
return sFilePath; HTz+K6&
} c\cZ]RZ
MM{_Ur7Q
$2z _{@Z
public void setSFilePath(String value) j<tq1?? [b
{ RE46k`44
sFilePath = value; :ipoD%@
} m4ApHM2
oB c@]T5>
e[Xq
public String getSFileName() KSs1CF'i
{ m8R=?U~!S
return sFileName; 4cCF\&yU
} O>DNC-m)i{
$*~Iu%Az
g?/XZ5$a5
public void setSFileName(String value) ){Mu~P
{ SKXBrD=-
sFileName = value; x.DzViP/
} ro| vh\y
{^q)^<#JT
z>vtEV))
public int getNSplitter() +6W(z3($
{ >`V}U*}*H
return nSplitter; e`UQz$4!
} 9\O(n>
`U`#I,Ln[
c5i%(!>
public void setNSplitter(int nCount) ,axDMMDI
{ _Sj}~H
nSplitter = nCount; ;q#]-^
} 32XS`Z
} ^nDal':*
6`nR5fh
gp< =Gmd
/* Jj"HpK>[
**Utility.java vahoSc;sw
*/ @YL}km&Fw
package NetFox; A|x:UQlu
?F$6;N6x
lxb8xY
public class Utility { /NBTvTI
H30OUrD
@Jv# fr
public Utility() #V 43=
{ gT1P*N;v
|'hLa
"G?9b
} RR25Q.c
-l*A
//线程睡眠 F&@|M(
public static void sleep(int nSecond) oKKz4
{ r?p{LF
try{ 9Vh_[^bR
Thread.sleep(nSecond); Z[IM<S9lz
} `^8*<+
catch(Exception e) Lar r}o=
{ 6$e]i|e
e.printStackTrace (); $p6N|p
} .LE+/n
} TgaYt\"i[
h`?k.{})M
//日志 wGXwzU
public static void log(String sMsg) wJIB$3OT
{ Ph)|j&]
System.err.println(sMsg); 6v47 QW|'
} O-GxUHwWr
%Y',|+Arx
z}APR@?`n8
public static void log(int sMsg) ,/o(|sks
{ /t{=8v~
System.err.println(sMsg); \|q-+4]@,
} ,YlQK;
} ^5)_wUf
B_~jA%0m'
P4%>k6X
/* f-+.;`H)T
**TestMethod.java )Qr6/c8}
*/ euZ(}+N&
package NetFox; ?`. XK}
M_&4]\PkCy
VD;j[~/Z
public class TestMethod { C_-E4I Z)
gM, &Spn
QMb^&?;s
public TestMethod() 5bfb!7-[i
{ ///xx/weblogic60b2_win.exe 5c;En6W
try{ jsWX 6(=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); on50+)uN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); qy9i9$8
SiteFileFetch fileFetch = new SiteFileFetch(bean); -A;w$j6*
fileFetch.start(); "^"'uO$
} csvOg[
catch(Exception e){e.printStackTrace ();} 1ZNNsB
FNJ!IkuR
Z3`2-r_=
} }xJR.]).KW
C1ZyB"{
o*;2mFP
public static void main(String[] args) #Q+R%p[D
{ 0x#E4v(UA
new TestMethod(); 5mIXyg 0:
} =h[yAf
} @YB85p"]J.
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