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)); aLhTaB-va
} zKgW9j<(
for(int i=0;i<nEndPos.length-1;i++) LF{qI?LG
{ *1%=?:$(r6
nEndPos = nStartPos[i+1]; P),%S9jP;
} vJXd{iQE@C
nEndPos[nEndPos.length-1] = nFileLength; H+_oK ]/
} r}03&h~Hc&
} -hhE`Y
[xM07%:
-7;RPHJs
//启动子线程 ~+^,o_hT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rA{h/T"
for(int i=0;i<nStartPos.length;i++) 28Q`O$=v
{ 4#4kfGoT
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uA\A4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O(WFjmHx
nStartPos,nEndPos,i); r|0C G^:C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Re,0RM\
fileSplitterFetch.start(); WDgp(Av!
} nE::9Yh8z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '6 w|z^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QR79^A@5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &tp5y}=n
nEndPos = " + nFileLength); $#"}g#u
// fileSplitterFetch[nPos.length-1].start(); hFQC%N.'
Zad+)~@!tq
-cIc&5CS
//等待子线程结束 6^|bKoN/ f
//int count = 0; "B)DX*-\?
//是否结束while循环 C|z`hNp
boolean breakWhile = false; VwtGHF'
^JYR^X>_
@RT yCr
while(!bStop) MS,H12h
{ bYG}CO
write_nPos(); yHT}rRS8
Utility.sleep(500); c WK@O>
breakWhile = true; o{>hOs &
VO++(G)
vP&*(WfO)
for(int i=0;i<nStartPos.length;i++) ?86h:9
{ X(Ef=:
if(!fileSplitterFetch.bDownOver) )Q7;)iPY#
{ u'?t'I
breakWhile = false; &QCqaJ-
break; V 9=y@`;
} 15nc
} +wT,dUin_<
if(breakWhile) B}r@xz
break; oJXZ}>>iT
iAup',AZg
[iL2c=_
//count++; hhYo9jTHW
//if(count>4) +R#*eo;o7
// siteStop(); hRc\&+#/
} 6jF~zI^
kv`x
1F[; )@
System.err.println("文件下载结束！"); j-yD;N
} MZL~IX
catch(Exception e){e.printStackTrace ();} /<|J\G21
} rr9HC]63
j:{<
& qd:o}
//获得文件长度 5zEl`h
public long getFileSize() 7g(rJGjtg
{ 5O)Z}
int nFileLength = -1; >@]E1Qfe
try{ 5<d Y,FvX
URL url = new URL(siteInfoBean.getSSiteURL()); P=u)Q _
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mHw1n=B
httpConnection.setRequestProperty("User-Agent","NetFox"); ;Oe6SNquT
_);1dcnR
Qy4AuMU2
int responseCode=httpConnection.getResponseCode(); Z/Mp=273
if(responseCode>=400) ;&:UxmTf
{ yfP&Q<|
processErrorCode(responseCode); r Ld,Izi
return -2; //-2 represent access is error U76:F?MH
} 2hU4g e?6
frGUT#9?n
: PQA9U|
String sHeader; O7rm(
O#u)~C?)8
'OF)`5sj
for(int i=1;;i++) I<[(hPQUf
{ qn4Dm ^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \a|gzC1G
//Utility.log(in.readLine()); YK"({Z>U
sHeader=httpConnection.getHeaderFieldKey(i); v SWqOv$
if(sHeader!=null) {/B) YR
{ M~ *E!
if(sHeader.equals("Content-Length")) m=%W<8[V
{ )[qY|yu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z.YsxbH3
break; NK,)"WE
} G.<9K9K
} Zvr(c|Q
else `=CF |I
break; A.z~wu%(
} a?+) K
} RsrZ1dhPvV
catch(IOException e){e.printStackTrace ();} >1joCG~
catch(Exception e){e.printStackTrace ();} &dOV0y_
Q[~O`Lz
^Jc~G~x4*
Utility.log(nFileLength); w8@MUz}/#
xES+m/?KlZ
6EPC$*Xp!
return nFileLength; /md`tqI>i<
} ]=]'*Z%
$dwv1@M2
%iJ6;V4
//保存下载信息（文件指针位置） L6Ynid.k
private void write_nPos() J!yc9Q
{ <u^41
try{ ! '2'db
output = new DataOutputStream(new FileOutputStream(tmpFile)); -B`;Sx
output.writeInt(nStartPos.length); bF B;N+>
for(int i=0;i<nStartPos.length;i++) xn6E f"
{ hXMC!~Th
// output.writeLong(nPos); q)@.f.
output.writeLong(fileSplitterFetch.nStartPos); O`@$YXuD
output.writeLong(fileSplitterFetch.nEndPos); EDnmYaa)dZ
} av`b8cGg
output.close(); tgrQ$Yjk
} lXB_HDY
catch(IOException e){e.printStackTrace ();} 1J<-P9 vk+
catch(Exception e){e.printStackTrace ();} :ye)%UU"|:
} C*c=@VAa
8<_WtDg
`5q`ibyPI
//读取保存的下载信息（文件指针位置） {]Lc]4J
private void read_nPos() (:[><-h.
{ zIdQ^vm8Q
try{ =U,;/f
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ylo@
int nCount = input.readInt(); kMI\GQW
nStartPos = new long[nCount]; czHO)uQ?d`
nEndPos = new long[nCount]; 9Ft)VX
for(int i=0;i<nStartPos.length;i++) 59EAqz[:
{ *[vf47)r!
nStartPos = input.readLong(); oh:t ex<
nEndPos = input.readLong(); ` 0\hm`
} Z?v9ub~%
input.close(); ? 4.W _
} y()#FRp7
catch(IOException e){e.printStackTrace ();} O+'Pq,hn
catch(Exception e){e.printStackTrace ();} HP?e?3.T
} 5_`.9@eh.
BwL:B\
071wo7
private void processErrorCode(int nErrorCode) ]k,fEn(
{ $@K+yOq+u
System.err.println("Error Code : " + nErrorCode); M5%xp.B
} 7Y!^88,f.
IE,g
Qh{=Z^r
//停止文件下载 gu"Agct4
public void siteStop() 'fg`td
{ ~xHr/:
bStop = true; xQmk2S` y
for(int i=0;i<nStartPos.length;i++) Kvk;D ]$
fileSplitterFetch.splitterStop(); [&Qrk8EN
(Ojg~P4;&
8fDnDA.e
} Dnd
} `NGCUGQ_7
//负责部分文件的抓取 #z5'5|3
**FileSplitterFetch.java *, {b]6v
*/ <p<gx*%
package NetFox; _$, .NK,6
$'&`k,a3|P
/}M@MbGMM
import java.io.*; Rf8|-G-}#
import java.net.*; B!8]\D
[[bMYD1eO
(jQL?
public class FileSplitterFetch extends Thread { @AyC0}
1"!<e$&$X
F<^,j7@
String sURL; //File URL ^Yn6kF
long nStartPos; //File Snippet Start Position x^C,xP[#Y;
long nEndPos; //File Snippet End Position @c{Z?>dUc#
int nThreadID; //Thread's ID 31bKgU{
boolean bDownOver = false; //Downing is over ]cA){^.Jz
boolean bStop = false; //Stop identical Q)Ppx7)
FileAccessI fileAccessI = null; //File Access interface NIYAcLa@n8
rW1>t+
}>p)|YT"/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3g5i5 G\
{ \l]jX: 9(
this.sURL = sURL; ;Y)?6^"
this.nStartPos = nStart; Z4t9q`}h
this.nEndPos = nEnd; ^ S%4R'
nThreadID = id; UQTt;RS*zS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s2d;601*b
} 9@:&E
k:d'aP3
i5)trSM|
public void run() qkR.{?x
{ GLk7#Y
while(nStartPos < nEndPos && !bStop) 3S.rIai+
{ }~A-ELe:
y`\/eX
xXHz)w
try{ op"Cc
URL url = new URL(sURL); }uZhoA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SmtH2%yI
httpConnection.setRequestProperty("User-Agent","NetFox"); O81})r*Y
String sProperty = "bytes="+nStartPos+"-"; w|RG
httpConnection.setRequestProperty("RANGE",sProperty); [#)$BXG~y
Utility.log(sProperty); #xts*{u-#
_b#9^2o
FiIN\
InputStream input = httpConnection.getInputStream(); (zTr/
//logResponseHead(httpConnection); hz )L+
u2!8'-Ai
qOk4qbl[
byte[] b = new byte[1024]; 2{&|%1Jg
int nRead; ,@[Q:fY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E=7"};
{ pX!S*(Q{
nStartPos += fileAccessI.write(b,0,nRead); <'s1+^LC
//if(nThreadID == 1) N;ssO,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X|8Yz3:o
} Kj'm<]u
\DfvNeF
*y`^Fc
Utility.log("Thread " + nThreadID + " is over!"); u/k#b2BqL
bDownOver = true; -;Hd_ ~O>j
//nPos = fileAccessI.write (b,0,nRead); we{*%8I;
} +z9;BPw%
catch(Exception e){e.printStackTrace ();} ;2bG-v'4vO
} eo,m ^&
} 44S<(Re
C#vh2'
(:@qn+ a
//打印回应的头信息 2{{M{#}S.
public void logResponseHead(HttpURLConnection con) C~6aX/:
{ f2yc]I<lr~
for(int i=1;;i++) b7"pm)6
{ SHhg&~B
String header=con.getHeaderFieldKey(i); A #ZaXu/:X
if(header!=null) "\> <UJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); a{]1H4+bQ
Utility.log(header+" : "+con.getHeaderField(header)); hBN!!a|l
else Iye
break; `~*qjA
} LsBDfp5/
} drN^-e
8zZR%fZ
<G6wpf8M
public void splitterStop() <Z#u_:5@
{ ~;U!?
bStop = true; &_!BMzp4
} *Z{W,8h*s
o F@{&
>Z>*Iz,LP
} ( 6r9y3'
^=W%G^jJy
rWa7"<`p
/* m*["
**FileAccess.java M0_K%Z(zaR
*//文件访问(定位，写) spFsrB
package NetFox; Tk+\Biq
import java.io.*; ,g^Bu{?
nA+[[(6
lt(,/
public class FileAccessI implements Serializable{ (|bht0
} #%sI"9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rLP4l~V
RandomAccessFile oSavedFile; rro,AS}
long nPos; 7tfFRUw
pk"JcUzR
@*_#zU#g
public FileAccessI() throws IOException h=)Im)
{ )(?s=<H
this("",0); xG<S2R2VQh
} S;*,V|#QD
>"ZTyrK
- FE)
public FileAccessI(String sName,long nPos) throws IOException x6F\|nb
{ !.p!
oSavedFile = new RandomAccessFile(sName,"rw"); @Z.Ne:*J
this.nPos = nPos; iiRK3m
oSavedFile.seek(nPos); ZZlR:D
} [i&z_e)
9E (>mN
cL=P((<K?
public synchronized int write(byte[] b,int nStart,int nLen) RV&2y=eb
{ Gt- -7S
int n = -1; 9:@os0^O
try{ |5g*pXu{
oSavedFile.write(b,nStart,nLen); }H^#}
n = nLen; d(fgv
} TcRnjsY$
catch(IOException e) L{(r@Vu
{ 7N'F]x
e.printStackTrace (); a^sR?.+3
} F3wRHq
M2V.FYV{j>
%zX'u.}8#
return n; )rj.WK.
} f1\x>W4z~\
n1$##=wK]
R HF;AX n
} R[#5E|` `9
\ iP[iE=
zBc7bbK
/* s"a*S\a;b
**SiteInfoBean.java P,wFib^1
*/ XY%8yII6
package NetFox; 85s{;3
0A}'.LI
oWJ}]ip
public class SiteInfoBean { ifBJ$x(B.
6aK%s{%3s
|y=CmNG,
private String sSiteURL; //Site's URL A.<X78!^
private String sFilePath; //Saved File's Path q F}5mUcZ4
private String sFileName; //Saved File's Name rj{'X /
private int nSplitter; //Count of Splited Downloading File hO(HwG?8t
[ BN2c
<{cPa\
public SiteInfoBean() u1<xt1K
{//nSplitter的缺省值为5 $_)f|\s
//default value of nSplitter is 5 <[pU rJfTr
this("","","",5); d$Mj5wN:q
} zpa'G1v
X\$M _b>O
Jg%sl&65
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =`/X Wem
{ eyo)Su
sSiteURL= sURL; iPkG=*Ip(%
sFilePath = sPath; ] c'owj
sFileName = sName; _$Fi]l!f
this.nSplitter = nSpiltter; [;X YT
~I'Z=Wo
*X<De
} jCa{WV:K}
qi/%&)GZ
c%B=TAs5c
public String getSSiteURL() WMI/Y9N
{ xr6Q5/p1
return sSiteURL; v}cm-_*v
} `zep`j&8^
NS&~n^*k<
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public void setSSiteURL(String value) i[YYR,X|
{ V<d'psb6
sSiteURL = value; cBm3|@7
} }!.7QpA$
-(1e!5_-@
tv;3~Y0i
public String getSFilePath() -7+Fb^"L
{ X^@d@xU4v
return sFilePath; [hFyu|I!
} Z:n33xh=<
.{8lG^0U<
n_c0=YH
public void setSFilePath(String value) w=f8UtY9@A
{ -R\}Q"
sFilePath = value; )s^XVs.-
} L\"=H4r
s5z@`M5'm
:;|x'[JoE?
public String getSFileName() {O"dj;RU
{ C6,Bqlio
return sFileName; c=Z#7?k=Uz
} n09|Jzv9
! q1Ql18n
{+`ep\.$&
public void setSFileName(String value) XRNL;X%}7
{ N;D+]_;0|
sFileName = value; X0=R @_KY
} 'kUrSM'*$N
$MsM$]~
[jLx}\]
public int getNSplitter() nl?|X2?C
{ 8[y7(Xw
return nSplitter; zd;xbH//)b
} w'qV~rN~tc
RP(FV<ot
C3memimN
public void setNSplitter(int nCount) o<!#1#n+:
{ pcEB-boI9
nSplitter = nCount; JHMj4Zkp
} LBM:>d5
} V5A7w V3~
yBr{nFOgdY
4H " *.l
/* Nd6N:1-
**Utility.java h2tzv~
*/ \zoJr)
package NetFox; iu:e>r
}- +;{u
8)H"w$jq
public class Utility { %R_8`4IQ
=|G PSRQ
5N[Y2
public Utility() }k,Si9O
{ *'`-plS7
3Yr
e~}+.B0
} ^7_<rs
>MhkNy
//线程睡眠 &MKv_
public static void sleep(int nSecond) ,Y&kW'2
{ p<J/J.E
try{ %Ajf|Go0/G
Thread.sleep(nSecond); lc/2!:g
} p~e6ah?1
catch(Exception e) Z2LG/R
{ {!EbGIh
e.printStackTrace (); "%Rx;xw|
} P|6m%y
} i\PN
j5RMS V
//日志 g|T' oK
public static void log(String sMsg) *k=}g][?
{ 2xjS;lpw
System.err.println(sMsg); k,&W5zBKe
} GN{.R7
*.K}`89T
~E`l4'g?
public static void log(int sMsg) N .SszZh
{ Nd( $s[
System.err.println(sMsg); BE m%x0y
} $B(B
} MW&;{m?2(
~o8$/%Oeb/
7aU*7!U
/* JY_' d,O
**TestMethod.java U}{r.MryFG
*/ M`5^v0,C
package NetFox; 6DExsB~@
eH6#'M4+\
TRQva8d?
public class TestMethod { KpK'?WhX7^
T[7-3[w<)
b.t]p
public TestMethod() 3W27R
{ ///xx/weblogic60b2_win.exe sDwSEg>#B
try{ t;? q#!uc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3XA^{&}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TQ>1u
SiteFileFetch fileFetch = new SiteFileFetch(bean); =izB :
fileFetch.start(); &KD m5p
} _-h3>.;h9
catch(Exception e){e.printStackTrace ();} ;=E3f^'s
KQ2]VN"?_
E.BMm/WH
} 3)`}#`T
%RJW@~!
6x.#K9@q4
public static void main(String[] args) B,A/ -B\
{ L1J"_.=P
new TestMethod(); LUCpZ3F1
} / AW]12_
} 19lx;^b
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