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)); )KRO=~Y
} q#\eL~k
for(int i=0;i<nEndPos.length-1;i++) WaMn[/{
{ d(a6vEL4
nEndPos = nStartPos[i+1]; Iz{AA-
} ((dG<
nEndPos[nEndPos.length-1] = nFileLength; `hlyN]L
} $]81s`
} &8&WY1cU
*pasI.2s#
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//启动子线程 1*-58N*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; vJq`l3&
for(int i=0;i<nStartPos.length;i++) T |j^
{ OClY,@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5. l&nt'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q>omCk%h
nStartPos,nEndPos,i); |J}~a8o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3\@6i'
fileSplitterFetch.start(); hV8A<VT
} Pq4sv`q)S
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SyYa_=En
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jEO;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \W@?revK
nEndPos = " + nFileLength); sox90o 7
// fileSplitterFetch[nPos.length-1].start(); \O/=g6w|t}
9)YG)A~<
hG;u8|uT^i
//等待子线程结束 5d4-95['_
//int count = 0; AARhGx|L<
//是否结束while循环 wOk:Q4OjL
boolean breakWhile = false; Yp ? 2<
Y0hL_46>
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while(!bStop) cL WM]\Y
{ 9Pb0Olh
write_nPos(); uPp(l4(+
Utility.sleep(500); ohh 1DsB
breakWhile = true; OQsH,'
=q"3a9pb7
Ahebr{u
for(int i=0;i<nStartPos.length;i++) uC;@Yi8
{ ss2:8up 99
if(!fileSplitterFetch.bDownOver) /n_HUY
{ Y.C*|p#
breakWhile = false; LQQhn{[D
break; }M~AkJL
} (?3(=+t
} dvj`%?=
if(breakWhile) ,,iQG' *
break; "M*\,IH
'/p5tw8
I%s/h4x^B[
//count++; E|fPI u
//if(count>4) $ `ho+
// siteStop(); . }1!MK5
} BW*zj=N%
3~S~)quwP
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System.err.println("文件下载结束！"); _6[NYv$"
} L`p[Dq.
catch(Exception e){e.printStackTrace ();} 5s|gKM
} Cv=0&S.
lubS{3<
7)]G"m{
//获得文件长度 A6Qi^TI
public long getFileSize() 4@Qq5kpk*
{ $H9xM
int nFileLength = -1; }Ag2c; aaq
try{ lwB!ti
URL url = new URL(siteInfoBean.getSSiteURL()); s-DtkO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l;C_A;y\
httpConnection.setRequestProperty("User-Agent","NetFox"); BdYh:
4q~E\l|.5
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int responseCode=httpConnection.getResponseCode(); r9U1O@c
if(responseCode>=400) 9PBmBP~
{ 5u8Sxfm",
processErrorCode(responseCode); }qg!Um0
return -2; //-2 represent access is error Tld{b
} >w'6ZDA*X
n#R!`*[
Ea !j-Lbo
String sHeader; St3~Y{aI|
,8 .`;
dvf*w:5K!
for(int i=1;;i++) (+@.L7>m+t
{ )Qc$UI8L
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *Zvw&y*
//Utility.log(in.readLine()); R}]FIu
sHeader=httpConnection.getHeaderFieldKey(i); | jkmh6
if(sHeader!=null) nk{1z\D{
{ *!Dzst-J3
if(sHeader.equals("Content-Length")) ubQ(O uM"
{ v$cD!`+k
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;Cy@TzO/|
break; 3m^BYr*y^
} 'ZDclz9}
} 4j*}|@x
else )<|TEp4r-
break; Y `{U45
} q}!4b'z^
} c'6H@m#=
catch(IOException e){e.printStackTrace ();} }B5I#Af7
catch(Exception e){e.printStackTrace ();} )0Lq>6j9
2Ar<(v$
zaZnL7ZJX
Utility.log(nFileLength); RD4)NN6y5}
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u%pief
return nFileLength; 8%4`Yj=
} EI;\of2,
t'J fiGM
(pmo[2kg
//保存下载信息（文件指针位置） q2Kn3{
private void write_nPos() jz)H?UuDY
{ |h7v}Y
try{ H07j&
output = new DataOutputStream(new FileOutputStream(tmpFile)); W)#`4a^xj7
output.writeInt(nStartPos.length); 5c"kLq6r
for(int i=0;i<nStartPos.length;i++) E;qwoTmul
{ VC.?]'OqD
// output.writeLong(nPos); qEAF!iB]L
output.writeLong(fileSplitterFetch.nStartPos); -:,h8JyMP
output.writeLong(fileSplitterFetch.nEndPos); r>Ln*R,9D
} I?>#neHc6
output.close(); @K9T )p]
} No7Q,p
catch(IOException e){e.printStackTrace ();} Y[!a82MTzn
catch(Exception e){e.printStackTrace ();} I?K0bs+6
} 0 OBkd
~K9U0ypH
+[ItkfSod!
//读取保存的下载信息（文件指针位置） nR7\ o(!
private void read_nPos() e0L;V@R
{ ,:`6x[ +
try{ '!R,)5l0h
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T?Y\~.+99
int nCount = input.readInt(); _#C}hwOR>X
nStartPos = new long[nCount]; Xo`1#6xsE
nEndPos = new long[nCount]; AJT0)FCpR
for(int i=0;i<nStartPos.length;i++) v\Ljm,+
{ |=LkV"_v
nStartPos = input.readLong(); FT~^$)8=
nEndPos = input.readLong(); 4i,SiFKB
} Bu1z$#AC
input.close(); zjA/Z(
} c #kV+n<
catch(IOException e){e.printStackTrace ();} *3$,f>W^
catch(Exception e){e.printStackTrace ();} HhvG#Sam!
} {<kG{i/
z(3"\ ^T
8|({ _Z
private void processErrorCode(int nErrorCode) MxRU6+a
{ D@^ZpN8r
System.err.println("Error Code : " + nErrorCode); uNbA>*c4M
} /<0D E22
$T6Qg(p
IMza 2
//停止文件下载 GcR`{ 3hO
public void siteStop() (5~C _Y
{ B$l`9!,
bStop = true; A ? M]5d
for(int i=0;i<nStartPos.length;i++) tWnm{mF
fileSplitterFetch.splitterStop(); ~8*oGG~s
YJ$ewK4E#.
B5:g{,C
} er0D5f R
} `VtwKt*
//负责部分文件的抓取 <+gl"lG
**FileSplitterFetch.java `a>vPW
*/ v=tj.Vg
package NetFox; ozC!q)j
M N#C2 qz
`?JgHk
import java.io.*; ~7pjk
import java.net.*; kA__*b}8UK
sg{D ?zl
vC:b?0s#(
public class FileSplitterFetch extends Thread { AiZFvn[n8
A+I&.\QAR
J\3} il N
String sURL; //File URL #[y<h3f]
long nStartPos; //File Snippet Start Position N}fUBX4k
long nEndPos; //File Snippet End Position N-`;\
int nThreadID; //Thread's ID hXm}d\
boolean bDownOver = false; //Downing is over ,dx)rZ*
boolean bStop = false; //Stop identical LUck>l\l
FileAccessI fileAccessI = null; //File Access interface ,g_onfY
6 ]Oxx{|}
0j(jJAE.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m> (h_j
{ SDHc[66'
this.sURL = sURL; nKB&|!
this.nStartPos = nStart; 87KrSZ
this.nEndPos = nEnd; c^O#O
nThreadID = id; Cc)P5\jh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *O>aqu
} UglG!1L
5xDN&su
]TgP!M&q
public void run() T:dm0iau
{ _AYC|R|
while(nStartPos < nEndPos && !bStop) EWIc|b:
{ kLt9;<L
;#s}b1
liqR#<
try{ DBJA}Cw
URL url = new URL(sURL); lVdT^"~3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *3O>J"
httpConnection.setRequestProperty("User-Agent","NetFox"); zN+*R;Ds
String sProperty = "bytes="+nStartPos+"-"; =kh>s$We
httpConnection.setRequestProperty("RANGE",sProperty); 1Xr"h:U_X
Utility.log(sProperty); u\R`IZ&O
QZ3(u<f
HDVl5X`j'
InputStream input = httpConnection.getInputStream(); (\t_Hs::a
//logResponseHead(httpConnection); V.ji _vX
ny(GTKoUz
eQFb$C]R}y
byte[] b = new byte[1024]; 7TkxvSL X
int nRead; vM7vf6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Y#&0x_Z
{ }l(m5
nStartPos += fileAccessI.write(b,0,nRead); i9eyrl+!
//if(nThreadID == 1) u'i%~(:$\)
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LkGf|yd_
} s!ZW'`4!z
:e]9T3Q
wB>S\~i
Utility.log("Thread " + nThreadID + " is over!"); <*"pra{3
bDownOver = true; Ae j
//nPos = fileAccessI.write (b,0,nRead); K- I\P6R`
} D!}K)T1~R
catch(Exception e){e.printStackTrace ();} /.)[9bQ<
} -~\.n
} 6f?BltFaN
5m^Hi}S_
4b2mtLn_
//打印回应的头信息 Mf:M3H%YV+
public void logResponseHead(HttpURLConnection con) BKQIo)g.G
{ /Y[o=Uyl
for(int i=1;;i++) -nk#d%a\
{ d)0LVa(
String header=con.getHeaderFieldKey(i); (+UmUx=
if(header!=null) LR3`=Z9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~#"7,rQp
Utility.log(header+" : "+con.getHeaderField(header)); )ojx_3j8
else v0`qMBr1y
break; h zZ-$IX X
} cc41b*ci$
} R6q4 ["
?Z Rkn+;
5, -pBep<
public void splitterStop() LiZdRr
{ ^+*GbY$'
bStop = true; hB?,7-
} VJN/#
x^)g'16`
^p 2.UW
} g={]Mzh
q*[!>\Z8
19F ;oFp
/* N )zPxQ
**FileAccess.java U['JFLF
*//文件访问(定位，写) | "Jx
package NetFox; j?\$G.Y
import java.io.*; gT(th9'+z
JG@L5f
EWb(uWC8h
public class FileAccessI implements Serializable{ V)0[`zJ
vZb|!#I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K/vxzHSl
RandomAccessFile oSavedFile; 894r;UA7
long nPos; q Vm"f,ruo
4D^ M<Xn
=`qRu
public FileAccessI() throws IOException #%?FM>
{ #)^^_
this("",0); ]8$#qDS@
} rH$eB/#F
|*^8~u3J"
uW}Hvj;0a*
public FileAccessI(String sName,long nPos) throws IOException URYZV8=B~
{ q.=^iz&m
oSavedFile = new RandomAccessFile(sName,"rw"); =oE_.ux\
this.nPos = nPos; 5LQk8NPh
oSavedFile.seek(nPos); JFkN=YR8
} WI1T?.Gc
:7p9t.R<$h
{I0w`xe
public synchronized int write(byte[] b,int nStart,int nLen) ePp[m zg6
{ SU%mmwES3
int n = -1; #V.ZdLo(
try{ PXw| L
oSavedFile.write(b,nStart,nLen); [ rQMD^:M$
n = nLen; }#yU'#|d
} C=N!z
catch(IOException e) rO/a,vV
{ "^;#f+0
e.printStackTrace (); HLjvKE=W
} $!!R:Wn/R
\U/v;Ijf
{(rf/:X!p
return n; X*pZNz&E
} T/[f5?p
lijB#1<8*
tNK^z7Dm
} A LXUaE.
Q |
,{k<JA{
/* ~?#~Ar
**SiteInfoBean.java 8r,9OM
*/ m_a^RB(
package NetFox; -=>sTMWpr
Hx$.9'Oq\Q
L-#e?Y}$J
public class SiteInfoBean { (O$}(Tn
D=$4/D:;
}@d>,1DU
private String sSiteURL; //Site's URL pe|X@o
private String sFilePath; //Saved File's Path 'gCJ[ce
private String sFileName; //Saved File's Name gs?8Wzh90*
private int nSplitter; //Count of Splited Downloading File 4~!Eje!
LU%#mY
c$9sF@K?
public SiteInfoBean() R7lYu\mA
{//nSplitter的缺省值为5 WFouoXlG0
//default value of nSplitter is 5 Te# ]Cn|
this("","","",5); PPEq6}
} >-!r9"8@
Qh*)pt]n
lbRzx4=\y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {$;2HbM(
{ @B?FE\
sSiteURL= sURL; _ w/_(k
sFilePath = sPath; tl|ijR
sFileName = sName; .}o~VT:!?Y
this.nSplitter = nSpiltter; Nj+a2[
;_}~%-_ ~
KYp[Gs
} iQqqs`K
tww=~!
alFNSRY
public String getSSiteURL() le.anJAr
{ :vpl+)n
return sSiteURL; xA92C
} H( vx/q
C,fY.CeI
Pb#P`L7OB
public void setSSiteURL(String value) vm8$:W2 }
{ !v0"$V5+i
sSiteURL = value; "# !D|[h0
} CphFv!k'Z
_Hc%4I
;`DD}j`
public String getSFilePath() Xh?4mKgu
{ 0LdJZP
return sFilePath; F>*{e
} +~N!9eMc
=~&VdPZ
%)?`{O~ h
public void setSFilePath(String value) *r;xw
{ 3f"C!l]Xu
sFilePath = value; @o6R[5(
} {?Od{d9
b]T@gJ4H=
YScvyh?E
public String getSFileName() >p0KFU
{ t8P PE
return sFileName; _g~2R#2Q
} :|rPT)yT]
)n>+m|IqY(
YlTaN,?j
public void setSFileName(String value) c;9.KCpwx
{ 4ZwKpQ6
sFileName = value; \w%@?Qik
} "N 3)Qr
J? .F\`N)
Zyu/|Og
public int getNSplitter() (!3;X"l
{ Hkege5{
return nSplitter; ##cnFQCB
} &dr@6-xaq
i)MEK#{
le8 #Z}p
public void setNSplitter(int nCount) 2Q@Y^t
{ y\D=Z N@
nSplitter = nCount; <.bRf
} 1Ipfw
} Xh F_]
D<>@ %"%
Ab2Q \+,
/* I-kWS4
**Utility.java 5wv fF.v
*/ BEUK}T K4
package NetFox; >&Y-u%}U
V%*b@zv
x6W`hpL
public class Utility { 1_hW#I\'
cG{L jt
eM2|c3/
public Utility() 'RbQj}@x
{ * ?]~ #
=^tA_AxVw
iX"C/L|JN
} s2REt$.q
6KRO{QK
//线程睡眠 [%pRfjM
public static void sleep(int nSecond) *z8|P#@
{ 0^3+P%(o@
try{ \~~}N4
Thread.sleep(nSecond); sILSey5`
} ]{GDS! )
catch(Exception e) #+k*1Jg
{ ~TqT}:,H
e.printStackTrace (); Z6Fp\aI8@
} ok{!+VCB5
} esX)"_xf
jQ+sn/ROp
//日志 fQdK]rLj
public static void log(String sMsg) t~hTp K*
{ Gh\q^?}
System.err.println(sMsg); =r9r~SR#
} KC#/Z2A|<
c{Ou^.yR
xfFg,9w8
public static void log(int sMsg) gE])!GMM3
{ M{mSd2
System.err.println(sMsg); 4a''Mi`u
} :J/M,3
} NxA)@9Q
Hy_;nN+e
4vWkT8HQ
/* =d)-Fd2li
**TestMethod.java @t*t+Vqw
*/ j Ux z
package NetFox; +>\id~c(
MTOy8 Im
eE@&ze>X
public class TestMethod { }4//@J?:
g(|{')8?d
T~4N+fK
public TestMethod() Qk1xUE
{ ///xx/weblogic60b2_win.exe hA1-){aw3q
try{ .(CP. d
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /i]y$^
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nNt1C
SiteFileFetch fileFetch = new SiteFileFetch(bean); Zd:Taieh@
fileFetch.start(); 0#*Lw }qi
} 04U")-\O
catch(Exception e){e.printStackTrace ();} /JkC+7H4
%9oYw9H!
O1'm@ q)
} 2lVHZ\G
"Wo,'8{v
NnT g3:.
public static void main(String[] args) i0jBZW"_1$
{ Bi,;lR5
new TestMethod(); GH1"xR4!
} [`RX*OH2
} s?R2B)a
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