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)); ~B"HI+:\L
} &DGz/o
for(int i=0;i<nEndPos.length-1;i++) x}c
{ .-tR <{ g
nEndPos = nStartPos[i+1]; g1[BrT,
} ^`";GnH0
nEndPos[nEndPos.length-1] = nFileLength; _!DH/?aU
} r/ g{j
} jF}kV%E
g%S/)R,,ct
7:uz{xPK6
//启动子线程 a4~B
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 1Xm>nF~
for(int i=0;i<nStartPos.length;i++) 0'pB7^y
{ ]7W!f 2@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DAWF =p]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q 9xA.*
nStartPos,nEndPos,i); ^#Q-?O
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V^[&4
fileSplitterFetch.start(); (W:@v&p
} $RYGAh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }l$zZ>.\H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r.#r!.6 q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", r1%{\<
nEndPos = " + nFileLength); bs)wxU`Q*
// fileSplitterFetch[nPos.length-1].start(); \l/}` w
*|\bS "
bs~P
//等待子线程结束 C@`#@1X
//int count = 0; Icg-rwa<Z
//是否结束while循环 b,~pwbHf
boolean breakWhile = false; ^t gjs$M|
-`\rDPGf
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while(!bStop) vMou`[\WlJ
{ ,s3|
write_nPos(); 6&SNFOX{@
Utility.sleep(500); zytN leyc
breakWhile = true; \z!lw
`IwZVz
~//9Nz~;3
for(int i=0;i<nStartPos.length;i++) l%GArH`
{ ~$T>,^K y
if(!fileSplitterFetch.bDownOver) aQx6;PC
{ /Ls|'2J<$
breakWhile = false; zu @|"f^`
break; 95@u|#n
} q5e(~@(z<`
} %+j/nA1%S
if(breakWhile) N)Q_z9b=
break; v0 :n:q
A9BoH[is7
qfJ2iE|o2.
//count++; dyn)KDS
//if(count>4) ~%>i lWaHB
// siteStop(); *'8q?R?7g
} dNt^lx
vkGF_aenk
|wuTw|
System.err.println("文件下载结束！"); A)n_ST0
} k0V]<#h87
catch(Exception e){e.printStackTrace ();} r7R'beiH
} z3S"1L7
=h-EN_[
\D z? h
//获得文件长度 /FXvrH(
public long getFileSize() F6yFKNK!n
{ pIK:$eN!/
int nFileLength = -1; fG>3gS6&
try{ *Ts$Hj[
URL url = new URL(siteInfoBean.getSSiteURL()); "QXnE^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kK4a;j.#
httpConnection.setRequestProperty("User-Agent","NetFox"); q6-o!>dLQ
]m 3cm
18F}3t??
int responseCode=httpConnection.getResponseCode(); 8o|C43Q_
if(responseCode>=400) ;AOLbmb)H4
{ =bD.5,F)
processErrorCode(responseCode); uNuFD|aQ.
return -2; //-2 represent access is error T=-UcF
} y-.{){uaD
:B5*?x
Gy):hGgN
String sHeader; QjSWl,{ $D
P<&bAsje
FNLS=4
for(int i=1;;i++) 4pT^*
{ MFa/%O_*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zC)JOykI%
//Utility.log(in.readLine()); oc,I,v
sHeader=httpConnection.getHeaderFieldKey(i); l([aKm#
if(sHeader!=null) /"La@M37
{ W3UxFs]$
if(sHeader.equals("Content-Length")) T:{&eWH
{ "A Bt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T_Tu>wQX
break; !~?/D
} MCibYvc[
} P2jh[a%
else dcmf~+T
break; =6ru%.8U,
} 7$%G3Q|)L
} $dI mA
catch(IOException e){e.printStackTrace ();} em,1Yn?
catch(Exception e){e.printStackTrace ();} d*Mqs}8
fNAW4I I}
iQ Xlz]'
Utility.log(nFileLength); Yn [ F:Z
{c3FJ5:
%Jh(5
return nFileLength; *Lz'<=DLoW
} 8f~x\.
w`8H=Hf
-V4{tIQY
//保存下载信息（文件指针位置） P]^OSPRg
private void write_nPos() !Q~>)$Cf^
{ b6k_u9m^E
try{ )s:kQ~+
output = new DataOutputStream(new FileOutputStream(tmpFile)); |0}Xb|+
output.writeInt(nStartPos.length); T\p>wiY2|F
for(int i=0;i<nStartPos.length;i++) )_C>hWvo_
{ /hqn>t
// output.writeLong(nPos); Z_bVCe{
output.writeLong(fileSplitterFetch.nStartPos); VS ECD;u4c
output.writeLong(fileSplitterFetch.nEndPos); baG_7>Q9H
} .up[wt gN
output.close(); U'F}k0h?\'
} Ek `bPQ5
catch(IOException e){e.printStackTrace ();} .GJbrz
catch(Exception e){e.printStackTrace ();} ly34aD/p~,
} -7w}+iS
bl>W i@GL
TEo
//读取保存的下载信息（文件指针位置） E-Xz
private void read_nPos() 9[VYd '
{ ;0m J4G
try{ iP9]b&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XYP RMa?
int nCount = input.readInt(); q j21#q .
nStartPos = new long[nCount]; Peph..8Z
nEndPos = new long[nCount]; }a!|n4|`
for(int i=0;i<nStartPos.length;i++) `T+>E0H(f
{ ;rT/gwg!
nStartPos = input.readLong(); >H;m[
nEndPos = input.readLong(); tx[;& ;
} _I;hM
input.close(); Eu&$Rq}
} ) q'D9x9
catch(IOException e){e.printStackTrace ();} '+$r7?dKP
catch(Exception e){e.printStackTrace ();} p2l@6\m\
} Ih5Y7<8b~
%Bm{ctf#)
k]:`<`/I_
private void processErrorCode(int nErrorCode) <7ANXHuSW
{ ` ~m/
System.err.println("Error Code : " + nErrorCode); lU Zj
} T7mT:z>:
N e{=KdzT
Gev\bQa
//停止文件下载 S_Nm?;P
public void siteStop() SbX^DAlB1
{ 'q;MhnU+
bStop = true; feB ?
for(int i=0;i<nStartPos.length;i++) 3C!|!N1Hn
fileSplitterFetch.splitterStop(); 5s^vC2$)
Wx3DWY;
r]xN&Ne5Q
} _z%\53h
} V+1c<LwT
//负责部分文件的抓取 r0k:RJP
**FileSplitterFetch.java C[znUI>
*/ zFFYl7]
package NetFox; r,IekFBs
P]}:E+E<.I
11QZ- ^
import java.io.*; j^b&Q
import java.net.*; {}'Jr1
YY tVp_)
Y'P^]Q=}_#
public class FileSplitterFetch extends Thread { k~<Ozx^AyY
e^\(bp+83
]6v7iuvI
String sURL; //File URL xv$fw>
long nStartPos; //File Snippet Start Position @(=?x:j
long nEndPos; //File Snippet End Position qOpwl*?x+
int nThreadID; //Thread's ID tOnOzD
boolean bDownOver = false; //Downing is over /KnIU|;
boolean bStop = false; //Stop identical o-_,l J7o^
FileAccessI fileAccessI = null; //File Access interface !X"nN9k
aDz% %%:r
+ah4 K(+3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3C=QWw?
{ dMjQV&
this.sURL = sURL; t4;gY298
this.nStartPos = nStart; ={o4lFe3v(
this.nEndPos = nEnd; {c?{M.R
nThreadID = id; ^|h_[>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 2.);OFk+
} 7?k3jDK
W=S^t_F
^oC>,%7
public void run() qrOesSdc
{ j3w~2q"r
while(nStartPos < nEndPos && !bStop) %<Qv?`B
{ &=%M("IlD
$ta"Ug.z
h-Ks:pcR
try{ 1n2Pr'|s
URL url = new URL(sURL); Bf^K?:r"V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w(+L&IBC
httpConnection.setRequestProperty("User-Agent","NetFox"); \Qnr0t@0
String sProperty = "bytes="+nStartPos+"-"; fOSJdX0e|Q
httpConnection.setRequestProperty("RANGE",sProperty); mBrZ{hqS
Utility.log(sProperty); h8M}}
/;q3Q#
;H%'K
InputStream input = httpConnection.getInputStream(); ,{iMF (Nj
//logResponseHead(httpConnection); po]<sB
g] IPNW^n
i/8OC
byte[] b = new byte[1024]; \N?lG q
int nRead; %ByqkY{5F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DD7D&@As
{ AxJqLSfyb,
nStartPos += fileAccessI.write(b,0,nRead); +('xzW
//if(nThreadID == 1) Xsb.xxK.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (Y&gse1}!
} ;gJAxVD<
<|WXFjn
33}p02#
Utility.log("Thread " + nThreadID + " is over!"); 2}P{7flDY
bDownOver = true; g(jn /Cx
//nPos = fileAccessI.write (b,0,nRead); lnMU5[g{
} kJ.7C
catch(Exception e){e.printStackTrace ();} HCktgL:E=
} c0jTQMe4yl
} J~@W":v
_,Q -)\
i[33u p
//打印回应的头信息 Mp5Z=2l5
public void logResponseHead(HttpURLConnection con) .Q</0*sp
{ IA=\c
for(int i=1;;i++) ?gK|R
{ :[_k .1-+
String header=con.getHeaderFieldKey(i); f0g_Gn $
if(header!=null) <[gN4x>'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :%fnJg(
Utility.log(header+" : "+con.getHeaderField(header)); SZxnYVY
else HsG3s?*
break; V+})$m*>
} LsMq&a-j2
} WT 5 2
tC+11M
>"zN`
public void splitterStop() 7|ACJv6%9
{ V2m= m}HQ
bStop = true; .)t*!$5=N
} (LVzE_`
'OhGSs|
b9Eb"
} =.`e4}u \X
W$D:mw7
PGTjOkx
/* ,k:>Z&:
**FileAccess.java D#>d+X$
*//文件访问(定位，写) gazX2P[D
package NetFox; _>t6]?*
import java.io.*; ob)c0Pz
eY:jVYG(
|mw3v>
public class FileAccessI implements Serializable{ oBPm^ob4
>T14 J'\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y]k{u\2A
RandomAccessFile oSavedFile; ,}^;q58
long nPos; _4lKd`
1q*=4O
D|C!KF (
public FileAccessI() throws IOException )h%tEY$AJ
{ Lp{uA4:=K
this("",0); b u/GaE~
} >ISBK[=H
)RT:u)N
-{*QjP;K
public FileAccessI(String sName,long nPos) throws IOException Fe 78YDx?
{ uH} }z!
oSavedFile = new RandomAccessFile(sName,"rw"); c`)[-
this.nPos = nPos; =#I/x=L:
oSavedFile.seek(nPos); KW36nY\7
} ph7]*W-
ge&!GO
v?q)E%5j
public synchronized int write(byte[] b,int nStart,int nLen) p"Di;3!y!
{ .Jc<Gg
int n = -1; YipL_&-
try{ Bv}i#D
oSavedFile.write(b,nStart,nLen); }SW>ysw'm
n = nLen; gF|u%_y-qt
} QIcc@PGT9a
catch(IOException e) V9D>Xh!0H
{ ,V+,3TT
e.printStackTrace (); \q|<\~A
} {k<mN Y
> a8'MK
A9y3B^\*
return n; [_tBv" z
} mw${3j~&
R6irL!akAd
HAcC& s8
} g % 8@pjk
MF5o\-&dN
HhqNpU
/* c38ENf
**SiteInfoBean.java }}d,xI
*/ WSx0o}
package NetFox; { =IAS}
E*UE?4FSw|
]6?6 k4@
public class SiteInfoBean { @t#Ju1Y
pJ@D}2u(
'!XVz$C
private String sSiteURL; //Site's URL oMb@)7
private String sFilePath; //Saved File's Path kfs[*ku
private String sFileName; //Saved File's Name ALp|fZ\vp
private int nSplitter; //Count of Splited Downloading File )#025>$z
U{&gV~
3c[TPD_:
public SiteInfoBean() 3ZL<6`YF
{//nSplitter的缺省值为5 @VKN6yHH
//default value of nSplitter is 5 B d?{ldg
this("","","",5); 3TnrPO1E
} o;{BI Q1
6tBe,'*
u'"]{.K>fb
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {bO O?pp
{ |Y;[)s =q
sSiteURL= sURL; >B+!fi'SS>
sFilePath = sPath; B5/"2i
sFileName = sName; %_ Vj'z~T
this.nSplitter = nSpiltter; 0-IL@Di`F
=a_ >")
]9$^=z%SE
} o+FDkqEN
WKONK;U+7
}Gh95HwE
public String getSSiteURL() O g!SFg*
{ M_f.e!?
return sSiteURL; @@#h-k%k-
} 6{?B`gm7g
'0jn|9l58
C\gKJW^]y@
public void setSSiteURL(String value) Pbl#ieZM
{ )&.Zxo;q=
sSiteURL = value; ;a~ e
} }6 MoC0
wp>L}!
\~I>@SG2W+
public String getSFilePath() zIbrw9G
{ 6[&x7"
return sFilePath; =]W[{@P
} f2Z(hYH~
9%^O-8!
?4YLt|sn
public void setSFilePath(String value) \vqqs
{ k[5:]5lp+
sFilePath = value; E8b:MY
} aJ$({ZN\#
^_G@a,
gE~LPwM
public String getSFileName() ow K)]t
{ `-w;/A"MJ
return sFileName; CsiRM8
} tk!5"`9N
J)="Im)
F4=V*/7
public void setSFileName(String value) >|g(/@IO
{ ?dAy_| zD
sFileName = value; EEj.Kch}4
} sc$I,|d2
@ x5LrQ_`r
O#x=iZI
public int getNSplitter() OzUo}QN
{ D7v_<
return nSplitter; ^D A<=C-[!
} s-JS[
lHc9D
yUEvva
public void setNSplitter(int nCount) nXfdf-
{ -Rbv#Y
nSplitter = nCount; *b\&R%6dR
} z2[{3Kd*
} K aNO&%qX
@k-iy-|3)
aS,
/* "43F.!P
**Utility.java N%!{n7`N:
*/ w L4P-4'
package NetFox; q0VR&b`?>D
QfRo`l/V9
c[a^fu!
public class Utility { uFn?U)
/^=8?wK
Nf)$K'/
public Utility() PUErvLt
{ /-Z}=
'>[Ut@lT;
arN=OB
} % !Ih=DZ
w[OUGn'
//线程睡眠 R$i-%3
public static void sleep(int nSecond) )8;At'q}
{ ~9n30j%]s
try{ L"}tJM.d
Thread.sleep(nSecond); .:~E.b
} z"f+;1
catch(Exception e) vF1Fcp.@
{ w$"^)EG,7
e.printStackTrace (); nB6 $*'
} O2"5\@HfE
} 4|;Ys-Q
(h'Bz6K
//日志 r0*Y~ KHw
public static void log(String sMsg) ;2[),k
{ o2!wz8
System.err.println(sMsg); DcN!u6sJ
} ~]SCf@pRk
63/a 0Yn
@W-0ybv
public static void log(int sMsg) C%H?vrR
{ afE)yu`
System.err.println(sMsg); ]Hg6Mz>Mj
} q1Mt5O}
} *auT_*
(#8B
z0@BBXQ`
/* ox5WboL
**TestMethod.java -^q;e]+J
*/ gFl@A}
package NetFox; N9 h|_ax
3Uej]}c
D7=Irz!O\7
public class TestMethod { !6,rN_a@Y
v[V7$.%5Q
v2k@yxt(
public TestMethod() tXcZl!3x
{ ///xx/weblogic60b2_win.exe s"R5'W\U
try{ N5zx#g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -F_cBu81V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t1wzSG
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5= T$h;O
fileFetch.start(); w)&?9?~
} rE]Nr ;Ys
catch(Exception e){e.printStackTrace ();} pog
NS-0-o|4#
o2[$XONTl
} 8:[ l1d86
|K9*><P?)2
9sI&d
public static void main(String[] args) *7b?.{
{ nw(R=C
new TestMethod(); vo(:g6$
} *HB 32 =qD
} gegM&Xo
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