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)); zHWSE7!
} ?B@;QjhjiJ
for(int i=0;i<nEndPos.length-1;i++) mN`YuR~
{ i[C~5}%
nEndPos = nStartPos[i+1]; 'PZ|:9FX!
} 9DQ)cy
nEndPos[nEndPos.length-1] = nFileLength; {",MCu_V
} 2 gq$C"
} GJi~y
ivO/;)=t
hjZ}C+=O
//启动子线程 9CGNn+~YI
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QZAB=rR
for(int i=0;i<nStartPos.length;i++) 9A,Z|q/z5
{ ;^ wd_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {n3EGSP#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uy_wp^
nStartPos,nEndPos,i); cxeghy:;U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3:/'t{ ^B
fileSplitterFetch.start(); oq/G`{`\
} gC%G;-gm
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Agh`]XQ2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4nfu6Dq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h<<>3A
nEndPos = " + nFileLength); S 6,4PP
// fileSplitterFetch[nPos.length-1].start(); HysS_/t~
Z#d&|5Xj
?rVy2!
//等待子线程结束 eO=s-]mk
//int count = 0; 6dH }]~a
//是否结束while循环 tbo>%kn
boolean breakWhile = false; Xy,lA4IP
a/Q$cOs
`cz2DR-"
while(!bStop) KAA-G2%M
{ n>3U_yt6b
write_nPos(); V!%jf:k
Utility.sleep(500); IH48|sa
breakWhile = true; t9 \x%=
#v#<itfFH
=.<@`1
for(int i=0;i<nStartPos.length;i++) WS-dS6Q}
{ oeSN9O
if(!fileSplitterFetch.bDownOver) qL6c`(0
{ 'mCe=Y
breakWhile = false; 2=0DCF;Bv
break; ^VW PdH/Fe
} UrlM%Jnq1
} TlL^7f}
if(breakWhile) 'AGto'Yy;
break; 1sE?YJP-
8*SDiZ
qs\2Z@;
//count++; 9Gy
//if(count>4) _cTh#t ^
// siteStop(); :Eh\NOc_O
} DBLk!~IF
8bK|:B#6,
_$NIp `d
System.err.println("文件下载结束！"); _EnwME{@
} C$Lu]pIL*
catch(Exception e){e.printStackTrace ();} t- u VZ!`\
} (2ur5uk+
#1c]PX
vr#+0:|
//获得文件长度 @Q&3L~K"
public long getFileSize() I +5)Jau^S
{ ~"pKe~h
int nFileLength = -1; fy@avo9
try{ Dih6mTP{
URL url = new URL(siteInfoBean.getSSiteURL()); &*G<a3Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j.~!dh$mg
httpConnection.setRequestProperty("User-Agent","NetFox"); (Q[fS:U
G CRz<)1
-U~
int responseCode=httpConnection.getResponseCode(); 2Y}?P+:%>
if(responseCode>=400) h'J|K^na
{ H|ozDA
processErrorCode(responseCode); rrg96WD
return -2; //-2 represent access is error AIb2k
} 1XG!$4DW
OJT1d-5p
I{JU-Jk|
String sHeader; 4p%A8%/q
M)*\a/6?{
6-`|:[Q~
for(int i=1;;i++) c,so`I3rI
{ u$%t)2+$4
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U<XSj#&8|
//Utility.log(in.readLine()); kK8itO
sHeader=httpConnection.getHeaderFieldKey(i); d\e7,"L*Q
if(sHeader!=null) ]&Z))H
{ d@w~[b
if(sHeader.equals("Content-Length")) iu**`WjI\
{ gh`m*@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `&0Wv0D0
break; G;> _<22
} *"9><lJ-!
} XxHx:mi
else w6`9fX6{h
break; umz;F
} T5urZq*R
} +% /s*EC'w
catch(IOException e){e.printStackTrace ();} 0CSv10Tg
catch(Exception e){e.printStackTrace ();} :^UFiUzrE
ys_`e
B1]bRxwn?
Utility.log(nFileLength); zYXV;
vVGDDDz/
OY[e.N t&
return nFileLength; Cs2;z:O]
} 9a'-Y
.xf<=ep
[c_|ob]
//保存下载信息（文件指针位置） Pxn,Qw*
private void write_nPos() P"sA
{ w\)|
try{ Qf@I)4'
output = new DataOutputStream(new FileOutputStream(tmpFile)); u3Gjg{-N7
output.writeInt(nStartPos.length); A^Kbsc
for(int i=0;i<nStartPos.length;i++) +cb6??H
{ NvM*h%ChM
// output.writeLong(nPos); .ROznCe}
output.writeLong(fileSplitterFetch.nStartPos); "#mBcQ;QLV
output.writeLong(fileSplitterFetch.nEndPos); S9HwIH\m
} kd"N29
output.close(); a^,(v
} G0E121`h
catch(IOException e){e.printStackTrace ();} ,C3,TkA]
catch(Exception e){e.printStackTrace ();} ~>9_(L
} q2HYiH^L
Q)"A-"y
a>\vUv*
//读取保存的下载信息（文件指针位置） Ym;*Y !~[
private void read_nPos() d1[ZHio2c?
{ +r3IN){jz
try{ Wg`R_>qQSm
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ZiLj=bh
int nCount = input.readInt(); [qsEUc+Z.'
nStartPos = new long[nCount]; SkU9ON
nEndPos = new long[nCount]; 0M\D[mg
for(int i=0;i<nStartPos.length;i++) vn/.}GkpU
{ H@]MXP[_
nStartPos = input.readLong(); mf'V)
nEndPos = input.readLong(); :[;hu}!&
} [w ;kkMJAy
input.close(); ybp -$e
} <w3!!+oK"
catch(IOException e){e.printStackTrace ();} Z"unF9`"1
catch(Exception e){e.printStackTrace ();} YBh'EL}P
} r'gOVi4t1*
{v3P9s(
yDNOtC|
private void processErrorCode(int nErrorCode) g+X}c/".
{ "`N-*;*W
System.err.println("Error Code : " + nErrorCode); \W,I?Kx$
} KZPEG!-5
B=|cS;bM$3
!ct4;.2 D
//停止文件下载 I-OJVZ( V
public void siteStop() h=-"SW
{ 1;VHM'
bStop = true; a&vY!vx3
for(int i=0;i<nStartPos.length;i++) 4tY ss
fileSplitterFetch.splitterStop(); 6;b~Ht
]l8^KX'
kQ]$%Lk[
} ,@5I:X!rR
} -_$$Te
//负责部分文件的抓取 =-p$jXVW%
**FileSplitterFetch.java 7g_]mG[6
*/ P;4w*((} ~
package NetFox; w&ak"GgV
w3$
#c2ymQm
import java.io.*; utr:J
import java.net.*; qe5feky
^j7azn
:%IoME
public class FileSplitterFetch extends Thread { Yw0[[N<SW
Ewg:HX7<(
@B}aN@!/
String sURL; //File URL _YRE (YZ/
long nStartPos; //File Snippet Start Position 43=,yz2Ef
long nEndPos; //File Snippet End Position $ MC)}l
int nThreadID; //Thread's ID 5atYOep
boolean bDownOver = false; //Downing is over )p*}e8L
boolean bStop = false; //Stop identical .1LCXW=
FileAccessI fileAccessI = null; //File Access interface F:aILx
W%\C_
{s;U~!3aY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ElUEteZ
{ d^`?ed\1
this.sURL = sURL; }V\N16f
this.nStartPos = nStart; m^qBxA
this.nEndPos = nEnd; K#.
nThreadID = id; zP<pEI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R4-~jgzx
} tsk)zP,<
c*~]zR>s!
13Lr}M&
public void run() W5R\Q,x6
{ c [5KG}
while(nStartPos < nEndPos && !bStop) )vxUT{;sH
{ )+fh-Ui
ZK)%l~J
33}oO,}t,
try{ fum0>tff
URL url = new URL(sURL); Tgl}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "^Ybs'-
httpConnection.setRequestProperty("User-Agent","NetFox"); G+F:99A
String sProperty = "bytes="+nStartPos+"-"; - |gmQG
httpConnection.setRequestProperty("RANGE",sProperty); 7VP32Eh[
Utility.log(sProperty); !kC*g
k!{p7*0
9YBv|A
InputStream input = httpConnection.getInputStream(); TjG4`:*y#m
//logResponseHead(httpConnection); aFLO{tr`
~ar=PmYV7
:<|<|qJWo
byte[] b = new byte[1024]; N;[>,0&z
int nRead; 1x,tu}<u^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3'X.}>o
{ (P`3 @H
nStartPos += fileAccessI.write(b,0,nRead); /soKucN"h
//if(nThreadID == 1) +$Rt+S BD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )(@Hd
} 9VbOQ{8
/Ju;MeE9
t2"FXTAq
Utility.log("Thread " + nThreadID + " is over!"); y a_<^O 9
bDownOver = true; wiBVuj#
//nPos = fileAccessI.write (b,0,nRead); Ot`VR&}
} qcT'nZ:
catch(Exception e){e.printStackTrace ();} y\x+
} 3*@5S]]
} [n/hkXa$\
bAx?&$
`HBf&Z
//打印回应的头信息 }RP@!=
public void logResponseHead(HttpURLConnection con) d \35a4l
{ GDuMY\1
for(int i=1;;i++) dc rSz4E|>
{ )Qvk*9OS
String header=con.getHeaderFieldKey(i); x)_0OR2lkp
if(header!=null) 28=O03q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =J~ x
Utility.log(header+" : "+con.getHeaderField(header)); 6VhjJJ
else [0D Et
break; _(KbiEB{
} 3@]SKfoo1
} >i6yl5s
aT`%;i^
3Gip<\$v
public void splitterStop() } GiHjzsR
{ 42qYg(tZ
bStop = true; Ggb5K8D*
} <=,6p>Eo[
-uy`!A
Kx%Sku<F'
} 2j&AiD
cSm%s
Nj 00W1
/* (V HL{rj
**FileAccess.java >orK';r<
*//文件访问(定位，写) ]i)j3WDz]
package NetFox; H_QsNf
import java.io.*; 5;{H&O9Q
@n": w2^B
eD#hpl
public class FileAccessI implements Serializable{ -bU oCF0
eET}r24
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \(vY%DL1:
RandomAccessFile oSavedFile; v 7x:dcV
long nPos; N~xLu8,
$81*^
)d>!"JB-
public FileAccessI() throws IOException PKzyV ;
{ j+ LawW-
this("",0); J`^I./
} oo.2Dn6z
}O4^Cc6
`9b7>Nn<
public FileAccessI(String sName,long nPos) throws IOException fP `b>]N_
{ 1N>|yQz
oSavedFile = new RandomAccessFile(sName,"rw"); I'0@viF"Nx
this.nPos = nPos; 9uQ 4u/F
oSavedFile.seek(nPos); IyLx0[:U
} J>bJ 449B
UCClWr
VH1d$
public synchronized int write(byte[] b,int nStart,int nLen) ..R-Ms)k=
{ }B.H|*uO
int n = -1; 7?%k7f
try{ v*[.a#1^
oSavedFile.write(b,nStart,nLen); AD<q%pu&H?
n = nLen; X<%Q"2hW
} x HhN
catch(IOException e) ;{%\9nS
{ {b
e.printStackTrace (); ~Wa6J4B{K
} =Fr(9(
)6J9J+%bi
])!o5`ltZ
return n; a0ObBe'
} ;{"+g)u
UTH_^HAN#G
Sh8"F@P8
} " _ka<R..
}-6)gWe
vt9)pMs
/* +qwjbA+
**SiteInfoBean.java LmnymcH
*/ <fFTY130:
package NetFox; dp*u9z~NA
F;<xnC{[
H?X|(r|+
public class SiteInfoBean { <>aw 1WM+
<h'5cO
oT>(V]*5
private String sSiteURL; //Site's URL ^cz(}N 6&
private String sFilePath; //Saved File's Path t>$kWd{9e;
private String sFileName; //Saved File's Name [a wjio
private int nSplitter; //Count of Splited Downloading File %eO0wa$a
]3l9:|
k>g_Z`%<
public SiteInfoBean() j_.5r&w
{//nSplitter的缺省值为5 t8+X%-r
//default value of nSplitter is 5 ]@Uq=?%
this("","","",5); 0PrLuejz
} t?'!$6
~S7D>D3S
X'qU*Eo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) jmFz51
{ E}nH1
sSiteURL= sURL; ^*Yh@4\{JH
sFilePath = sPath; ^kB8F"X
sFileName = sName; $H9%J
this.nSplitter = nSpiltter; J:zU,IIJ
PIwFF}<(
A*/HjTX
} <t \H^H!
N#a$t&
aN8|J?JH
public String getSSiteURL() vz7J-CH
{ [CXrSST")E
return sSiteURL; T"DlT/\
} [.uG5%fa
lUvpszH=
h*u
public void setSSiteURL(String value) M 4?ig}kh
{ 1R1z
sSiteURL = value; u*ObwcI/Bn
} 283F)T\Rv
([m mPyp>L
`yH<E+
public String getSFilePath() OZ~5*v
{ io-![^{
return sFilePath; &N\jG373
} f>UXD
hUp.tK:X7o
z;|A(*Y
public void setSFilePath(String value) + |#O@k
{ F.=2u"[*&
sFilePath = value; ~5CBEIF(NS
} YH\OFg@7
Kk-S}.E
%R}.#,Suo
public String getSFileName() ?7.7`1m!v
{ _0]S69lp
return sFileName; YSTv\y
} IJ(
d\R,Q
.ZVUd84B
public void setSFileName(String value) ;kS&A(
{ ~&7MkkftM
sFileName = value; 06c>$1-?
} OHb[qX\
+RYls|f
j/_s"}m{
public int getNSplitter() LHkc7X$
{ e :%ieH<
return nSplitter; 34%RZG_o'
} odjT:Vr
gT0BkwIV
VFURAYS
public void setNSplitter(int nCount) FrL]^59a
{ e%@~MQ-
nSplitter = nCount; >aj7||K
} +#lM
} ^h~x)@=
pgE}NlW
v*SEb~[
/* N343qU
**Utility.java Py@wJEo
*/ gy 3i+J
package NetFox; a1t4Dd
P3)Nl^/
X.f>'0i
public class Utility { O&4SCVZp
-bT)]gA2
%yW3VL
public Utility() ifUGY[L
{ C/vIEYG4
AGQ#$fh>7=
YW_Q\|p]M
} 1m:XR0P
Sjyoc<Uo
//线程睡眠 V )x$|!(
public static void sleep(int nSecond) D6>2s\:>vp
{ GVYBa_gx
try{ \]2]/=2tLd
Thread.sleep(nSecond); #Ssx!+q?
} mpuq 9)6
catch(Exception e) YaKeq5%y
{ :D%"EJ
e.printStackTrace (); M<.d8?p )
} QS` PpyBkd
} jV>raCK_
LcSX*MC
//日志 [y'f|XN
public static void log(String sMsg) A+"ia1p,}
{ TDFkxB>
System.err.println(sMsg); #LL?IRH9^
} _aad=BrMK
k.vBj~xU
9F)z4
public static void log(int sMsg) J'SZ
{ u09:Z{tL;@
System.err.println(sMsg); F+,~v-
} }z _
} "$ Y_UJT7
jkiFLtB@V
bx{$Y_L+p
/* w)kNkD
**TestMethod.java dZ rAn
*/ ~sl{|E
package NetFox; =vDEfO/T
Rs-]N1V
86 W9rR
public class TestMethod { F)&@P-9+
aY'C%^h]
]iN'x?Fo
public TestMethod() :PIF07$xl
{ ///xx/weblogic60b2_win.exe :km61
try{ DcoX+8 7
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7n8~K3~;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B_nVP
SiteFileFetch fileFetch = new SiteFileFetch(bean); Hfwq/Is
fileFetch.start(); kP#B5K_U|
} Ne8Cgp
catch(Exception e){e.printStackTrace ();} M dZ&A}S
3D!5T8 @
AsAT_yv#
} 2XFU1 AW
<j*;.yyC
iOR_[y,
public static void main(String[] args) F(k.,0Nc
{ !MYSfPdS
new TestMethod(); hAYTj0GZ
} T (OW
} v, n$^R
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