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)); :F7k{~
} b8N[."~:
for(int i=0;i<nEndPos.length-1;i++) ).NcLJw_
{ CJ9cCtA
nEndPos = nStartPos[i+1]; Vl{~@G,@
} 8"km_[JE e
nEndPos[nEndPos.length-1] = nFileLength; c$Xe.:QY
} (VYR!(17
} DO&+=o`"
83KfM!w
NqJ<!q)
//启动子线程 W!/vm
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Sc&)~h}YF
for(int i=0;i<nStartPos.length;i++) 1z~k1usRK
{ &GdL 9!hH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =5y`(0 I`U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p-5Pas
nStartPos,nEndPos,i); 9W1;Kb|Z<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T[0V%Br{d+
fileSplitterFetch.start(); 5Noe/6
} `*e4m
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6R;)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W\it+/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", DeOXM=&z
nEndPos = " + nFileLength); 1@A7h$1P
// fileSplitterFetch[nPos.length-1].start(); -|m$YrzG
xi680'
owE<7TGPI?
//等待子线程结束 |x &Z~y
//int count = 0; XVQL.A7
//是否结束while循环 ?^LG hdR
boolean breakWhile = false; |EF>Y9
b/}'Vf[
<9ma(PFa
while(!bStop) )K{o<m~WAo
{ ;#3ekl{-g
write_nPos(); uuu\f*<
Utility.sleep(500); IWAj Mwo
breakWhile = true; X_D6eYF
f;.SSiT
zzX<?6MS
for(int i=0;i<nStartPos.length;i++) \Y*!f|=of
{ |/@0~O(6
if(!fileSplitterFetch.bDownOver) A)8rk_92Q
{ qE>i,|rP`
breakWhile = false; {bN Y
break; 6 -]>]Hr-
} SK's!m:r=
} x.I][(}
if(breakWhile) kr^0% A
break; G9\EZ\x!
'.pgXsC:=?
__8&Jv\
//count++; KzV.+f
//if(count>4) FyCBNtCv
// siteStop(); e\`wlaP,
} z~F37]W3[
{3_Gjb5\\4
}A-{6Qe
System.err.println("文件下载结束！"); mv{<'
} M9gOoYf,~
catch(Exception e){e.printStackTrace ();} y)P&]&"?
} nt7|f,_J
;:P7}v fz!
d>UnJ)V}
//获得文件长度 R0{Qy*YQ`
public long getFileSize() !6lOIgn
{ ze&#i6S
int nFileLength = -1; pg+b[7
try{ 5`"iq "5Cf
URL url = new URL(siteInfoBean.getSSiteURL()); Qe_+r(3)k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2zhn`m
httpConnection.setRequestProperty("User-Agent","NetFox"); \fTTkpM
fTBVvY4(
bV_j`:MD
int responseCode=httpConnection.getResponseCode(); i&JpM]N
if(responseCode>=400) C?/r;
{ J2m"1gq,
processErrorCode(responseCode); 22z1g(;@
return -2; //-2 represent access is error DacN{r"3
} yx2z%E
YV-j/U{&
(i\)|c/a7
String sHeader; a~,Kz\Tt
"9w}dQ
fTcY"A,2
for(int i=1;;i++) -OWZ6#v(
{ ~Po<(A}`f
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4h;4!I|
//Utility.log(in.readLine()); n,CD
sHeader=httpConnection.getHeaderFieldKey(i); DY8(g=TI|1
if(sHeader!=null) Yr=8!iR$
{ GLCAiSMz[
if(sHeader.equals("Content-Length")) rkq#7
{ RB[/q:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [_V:)
break; syRN4
} iA9 E^
} H37QgApB
else 9:Si] Pp+S
break; 19p8B&
} uxb:^d?D!
} "CBRPp
catch(IOException e){e.printStackTrace ();} #BsW
catch(Exception e){e.printStackTrace ();} 6x/s|RWL1
}-74f
aZ6'|S;
Utility.log(nFileLength); <6/= y1QC)
KU]ok '
Ps3~{zH`
return nFileLength; gGEIK0\{
} z3W3=@
P3!Atnv2
z6I%wh
//保存下载信息（文件指针位置） d*2u}1Jo8
private void write_nPos() NO2(vE
{ Vc _:*
try{ 6Cv.5Vhx
output = new DataOutputStream(new FileOutputStream(tmpFile)); IB8gDP2
output.writeInt(nStartPos.length); TcJ$[
for(int i=0;i<nStartPos.length;i++) ^&Q<tN7
{ E=]]b;u-n
// output.writeLong(nPos); et` 0Je
output.writeLong(fileSplitterFetch.nStartPos); 5]d{6Nc3P
output.writeLong(fileSplitterFetch.nEndPos); )S*1C@
} b# u8\H
output.close(); f!x[ln<
} >?I/;R.-
catch(IOException e){e.printStackTrace ();} 5$%XvM
catch(Exception e){e.printStackTrace ();} doR4nRl9
} 0q#"clw
n1,S_Hs
L5f$TLw h;
//读取保存的下载信息（文件指针位置） :RiF3h(
private void read_nPos() JhP\u3 QE
{ h&`y$Jj
try{ _~&9*D$ {>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <^c3}
int nCount = input.readInt(); lL0M^Nv
nStartPos = new long[nCount]; 2"X~ju
nEndPos = new long[nCount]; id?E)Jy
for(int i=0;i<nStartPos.length;i++) OhFW*v
{ "(f`U.
nStartPos = input.readLong(); s$ z2 c
nEndPos = input.readLong(); {$33B'wk
} ^_W40/c3
input.close(); 2khh4?|\
} e;h,V(
catch(IOException e){e.printStackTrace ();} RV;!05^<
catch(Exception e){e.printStackTrace ();} :$%>4+l
} Qnt5HSSt
`*_CElpP"
pRrHuLj^
private void processErrorCode(int nErrorCode) Z9[+'ZWt
{ ]C!?HQ{bsf
System.err.println("Error Code : " + nErrorCode); z:}nBCmLV
} z_&P?+"Df
S-c ^eLzQ
}`_(<H
//停止文件下载 2hq\n<
public void siteStop() cP rwW6
{ vFhz!P~
bStop = true; e.8$ga{
for(int i=0;i<nStartPos.length;i++) 7u|B ](FS
fileSplitterFetch.splitterStop(); wk @,wOt
[_.n$p-
24B<[lSK
} iKAusWj
} WD.U"YI8y
//负责部分文件的抓取 `q_<Im%I
**FileSplitterFetch.java !Z|($21W
*/ qINTCm j
package NetFox; izuF !9
/{*$JF
Ch5+N6c^
import java.io.*; :NE/Ddgc'
import java.net.*; f<=Fe:1.
^$NJD
6R4<J%$P
public class FileSplitterFetch extends Thread { ^R~~L
Q2QY* A
n>FY?
String sURL; //File URL e|lD:_1i
long nStartPos; //File Snippet Start Position s&Yi 6:J
long nEndPos; //File Snippet End Position 8ObeiVXf)
int nThreadID; //Thread's ID f^b K=#
boolean bDownOver = false; //Downing is over ^sClz*%?
boolean bStop = false; //Stop identical q>s`uFRg(
FileAccessI fileAccessI = null; //File Access interface ,:GN;sIXg
'*T]fND4
LW:1/w&pv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException #/70!+J_UF
{ (kw5>c7
this.sURL = sURL; 93o;n1rS
this.nStartPos = nStart; OH'ea5xq
this.nEndPos = nEnd; @~:8ye
nThreadID = id; mYv(R!37'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z :nbZHByh
} /nQ`&q
s([dGD$i
&JhX+'U
public void run() DL8x":;
{ @S3f:s0~D
while(nStartPos < nEndPos && !bStop) Yj3I5RG
{ XKU=oI0\j
<<zI\+V
)^x K
try{ vhgLcrn
URL url = new URL(sURL); {C3Y7<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3yO=S0`
httpConnection.setRequestProperty("User-Agent","NetFox"); KoBW}x9Jp
String sProperty = "bytes="+nStartPos+"-"; DuF"*R~et
httpConnection.setRequestProperty("RANGE",sProperty); {hdPhL
Utility.log(sProperty); ~Xv=9@,h
`dW]4>`O
w0J|u'H
InputStream input = httpConnection.getInputStream(); \".^K5Pm
//logResponseHead(httpConnection); zm#nV Y`
.\:J~(
$xgBKD
byte[] b = new byte[1024]; \'v(Xp6
int nRead; Z-X?JA\&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {?8B,G2r
{ QP(BZJC
nStartPos += fileAccessI.write(b,0,nRead); (z7+|JE.
//if(nThreadID == 1) `/IKdO*!S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q|(W-h+
} kOrl\_!z3
!0}\&<8/m
WO*9+\[v
Utility.log("Thread " + nThreadID + " is over!"); LKF/u` 0dP
bDownOver = true; ^J/)6/TMXm
//nPos = fileAccessI.write (b,0,nRead); zI;0&
} WF2-$`x
catch(Exception e){e.printStackTrace ();} 4P8*k[.
} Jjm|9|C,
} K[?Xm"4
n1v5Q2xw
g@ith&*=h
//打印回应的头信息 [(mlv42"
public void logResponseHead(HttpURLConnection con) 3iX?~
{ ~mp0B9L%
for(int i=1;;i++) uGP(R=H
{ rofNZ;nu
String header=con.getHeaderFieldKey(i); q_fam,9
if(header!=null) }JgYCsF/f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 8|g<X1H{M
Utility.log(header+" : "+con.getHeaderField(header)); 8y2+&#$
else dK9Zg,DZL
break; !{%:qQiA
} $jzFc!rs
} hZ$t$3
dp5cDF}l
ku&k'V
public void splitterStop() ``K#}3
{ Xyx"A(v^l
bStop = true; ~Ci{3j :]
} iz[gHB
MgMD\
lS5ny
} <i. apBH
{S.>BXX
V"KS[>>f
/* *%FA:Y
**FileAccess.java %&<LNEiUN
*//文件访问(定位，写) V-yUJ#f8[
package NetFox; *f+: <=i
import java.io.*; 8At<Wic
}j{!-&
t#E}NR
public class FileAccessI implements Serializable{ Dt}rR[yJ
_=XX~^I,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %yS3&Ju
RandomAccessFile oSavedFile; 3251Vq %
long nPos; 1R%1h9I4'
ro~+j}*
.?W5{U
public FileAccessI() throws IOException @z`@f"l
{ JK_OZ
this("",0); ))h6~1`
} Yl cbW0'c
1OaXo!
@* ust>7
public FileAccessI(String sName,long nPos) throws IOException e /K#>,
{ GIwh@4;
oSavedFile = new RandomAccessFile(sName,"rw"); 8(U{2B8>\%
this.nPos = nPos; ;3'NMk
oSavedFile.seek(nPos); MjL)IgT
} }?@5W,
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\%jVg\4'
public synchronized int write(byte[] b,int nStart,int nLen) ,\)a_@@k
{ +>f<EPGn
int n = -1; Q9F)
try{ W&Y"K)`
oSavedFile.write(b,nStart,nLen); VyLH"cCv
n = nLen; eDKxn8+(H
} D@ek9ARAq
catch(IOException e) I27,mS+]
{ 'I}:!Z
e.printStackTrace (); QCOo
} .^(/n9|o-
+C]&2zc.
j{++6<tr
return n; ?X$,fQ#F|
} giY80!GX
3INI?y}t
<U Zd;e@
} 7L5P%zLtB
8T[ 6J{|C
YNdrWBf)
/* uzOYVN$t
**SiteInfoBean.java Dh|w^Q
*/ }GwVKAjP
package NetFox; Ka!I`Yf
I<oL}f
>`RRP}u=u
public class SiteInfoBean { Ut@RGg+f8
>H][.@LyR
\*T"M*;
private String sSiteURL; //Site's URL 4vnUN
private String sFilePath; //Saved File's Path I,@r5tKo
private String sFileName; //Saved File's Name F0Jx(
private int nSplitter; //Count of Splited Downloading File ChrY"
OTWkUB{
KxGX\
public SiteInfoBean() {2d_"lHBt
{//nSplitter的缺省值为5 $RX'(/
//default value of nSplitter is 5 &n2e
this("","","",5); "Y:/= Gx
} l~:v (R5
(46 {r}_O
:;;E<74e i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) DPgm%Xq9(!
{ 6c4&VW
sSiteURL= sURL; 1k8x%5p
sFilePath = sPath; 9Ru;`
sFileName = sName; }Nj97R
this.nSplitter = nSpiltter; j1$8#/r;c
RF}X ER
|`k .y]9
} <E|s\u
<Q< AwP
vYmSKS
public String getSSiteURL() -F/st
{ BcWcdr+}9
return sSiteURL; `bI)<B
} `1` f*d v
<Cpp?DW_
YB))S!;Ok
public void setSSiteURL(String value) ^WYQ]@rh3
{ QWnndI_4p
sSiteURL = value; R@Y=o].2
} MZv]s
ZM#=`k9
_mE^rT
public String getSFilePath() | $^;wP
{ U 5w:"x
return sFilePath; LHCsk{3
} CBT>"sYE1
5MTgK=c
Lm*VN~2
public void setSFilePath(String value) CJknJn3m&
{ I+ l%Sn#\
sFilePath = value; IakKi4(
} `g''rfk}
!eR3@%4
!cW[G/W8
public String getSFileName() w FtN+
{ 10[Jl5+t
return sFileName; PaB!,<A
} 8iQ[9
L6P1L)
mg:!4O$K
public void setSFileName(String value) Tpp&
{ `b5 @}',
sFileName = value; @DAF 6ygs
} ;Q0bT`/X
#Doq P:
;$j7H&UNQj
public int getNSplitter() H5>hx{
{ h&@R| N
return nSplitter; ]uL+&(cr
} &p UZDjo?
X<OSN&d
Q/>L_S
public void setNSplitter(int nCount) *!e(A ]&
{ `\|ssC8u
nSplitter = nCount; )u ?' ;
} d5I f"8`@
} NVV}6TUV
hPhZUL%
.S\&L-{
/* 0o&MB Dp
**Utility.java W1aa:hEf
*/ C.MoKa3
package NetFox; 1r)kR@!LNG
YA(@5CZ
8G%yB}pa
public class Utility { )x,8D ~p'
h #Z4pN8T3
'rP]Nw
public Utility() I8
{ u0`o A
%~|HFYd
"%2xR[NF
} ~vdkFc(8B
~q0*"\Ff
//线程睡眠 4pz|1Hw7
public static void sleep(int nSecond) }A$WO{2
{ s Wjy6;
try{ + bhym+
Thread.sleep(nSecond); vdoZ&Tu
} )wXuwdc[
catch(Exception e) Eu<1Bse;
{ Mq%,lJA\
e.printStackTrace (); HHk)ZfWRo
} 2i#Sn'1
} (kBP(2V
2Nc>6
//日志 -5G)?J/*
public static void log(String sMsg) :B*}^g
{ ^ ?hA@{T/1
System.err.println(sMsg); %%%fL;-y
} Wk;5/
Pj#'}ru!
{y kYW%3s
public static void log(int sMsg) XV>JD/K2
{ YOyX[&oi
System.err.println(sMsg); rPzQ8<
} sPAg)6&M
} 7[v%GoE
+m\|e{G
}peBR80tQ
/* [BbutGvj
**TestMethod.java Fnx`Ri
*/ J<j&;:IRd
package NetFox; dpZ;l 9
9$K;Raz%
?0*8RK
public class TestMethod { I~eSZ?$s#
Z-=YM P ]Q
{C*\O)Gep
public TestMethod() "7%:sty
{ ///xx/weblogic60b2_win.exe omZO+=8Q
try{ -PB[-CX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [^H"FA[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o(A|)c4k
SiteFileFetch fileFetch = new SiteFileFetch(bean); '$|UwT`s
fileFetch.start(); 8Q`WB0E<|
} [jx0-3s:X
catch(Exception e){e.printStackTrace ();} Zwt;d5U
D6D1S/:ij'
3-s}6<0v1
} 9W*+SlH@!
>gtQw!
>v;8~pgO
public static void main(String[] args) :y]Omp
{ Y[ reD
new TestMethod(); H!e 3~+)
} &`|:L(+
} n ?[/ufl
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