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)); |Ew~3-u!
} ^* xhbM;
for(int i=0;i<nEndPos.length-1;i++) d:U2b"k=/u
{ YPjjSi:#
nEndPos = nStartPos[i+1]; K%XQdMv
} $yZ(c#L
nEndPos[nEndPos.length-1] = nFileLength; 9^;)~ G
} \Bg;^6U
} ^x! N]
iK#5nY].
Q\P?[i]
//启动子线程 ^`W8>czi
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5$v,%~$Xds
for(int i=0;i<nStartPos.length;i++) '^TQ Ubw
{ y?ps+ce93
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OZ/P@`kN.f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {Z529Ns
nStartPos,nEndPos,i); D[m+=-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); P,$|.pd'
fileSplitterFetch.start(); A]z~Dw3
} {Hv/|.),hu
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Px!M^ T!Pi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D!K){E
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ST#OO!
nEndPos = " + nFileLength); (XQBBt
// fileSplitterFetch[nPos.length-1].start(); q'07
)zFPf]gz
&8l"Dl
//等待子线程结束 j^t#>tZS
//int count = 0; F__(iXxC
//是否结束while循环 z,6X{=
boolean breakWhile = false; x=UwyZ
uafSz@`
ICJp-
while(!bStop) xKilTh_.6
{ ?!N@%R>5rN
write_nPos(); M^i^_}~S;
Utility.sleep(500); ;1S~'B&1Q
breakWhile = true; 52*9q!
EJdl%j
`^rN"\
for(int i=0;i<nStartPos.length;i++) =~)J:x\F
{ X+'z@xpj
if(!fileSplitterFetch.bDownOver) NTnjVU }
{ =@98Gl9!
breakWhile = false; Js`xTH'
break; .L,xqd[zC
} 0i76(2
} 7J 0=HbH
if(breakWhile) QKj-"y[
break; `zr%+
bNUb
mkA1Sh{hX>
//count++; //SH=>w2
//if(count>4) x@-bY
// siteStop(); T-0[P;
} + _=&7
$ekB+ t:cj
?2Q9z-$
System.err.println("文件下载结束！"); tBtG- X2
} ;.=ZwM]C
catch(Exception e){e.printStackTrace ();} 3GH@|id
} 3?Ml]=u
=hs !t|(*
n=HId:XT
//获得文件长度 `Qf$]Eoft
public long getFileSize() Kq`C5
{ y^7ol;t
int nFileLength = -1; C'HW`rh.^
try{ C%s+o0b
URL url = new URL(siteInfoBean.getSSiteURL()); qIbp0`m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0P(U^rkR~
httpConnection.setRequestProperty("User-Agent","NetFox"); /H_,1Fu|
E0;KTcZi
kC=e>v
int responseCode=httpConnection.getResponseCode(); ~!*xi
if(responseCode>=400) < ag|#
{ M;BDo(1
processErrorCode(responseCode); NVEjUt/
return -2; //-2 represent access is error +-~:E_G
} =B}a +0u!
#WBlEVx;Z
2OXcP!\Y
String sHeader; @a AR99M
#Y*?kTF
41c]o<!=)j
for(int i=1;;i++) -ZTe#@J
{ I~LN)hqdo
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); w\ hl2JTy
//Utility.log(in.readLine()); pYtG%<
sHeader=httpConnection.getHeaderFieldKey(i); }b9"&io
if(sHeader!=null) c7$L:
{ )7U^&I,
if(sHeader.equals("Content-Length")) [@!.(Hp
{ 8|>$M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :r?gD2q
break; &RRHmJI:
} g7($lt>
} sV8}Gv a
else XcOfQs
break; =0te.io)3O
} 7Ao9MF-
} gWt}q-@nRR
catch(IOException e){e.printStackTrace ();} J%G EIe|
catch(Exception e){e.printStackTrace ();} vwVK^B
~F?vf@k
/az}<r8
Utility.log(nFileLength); ]*I:N
Z`5jX;Z!
#;9I3,@/Y
return nFileLength; ?2hS<qXX
} m`"^d #
%2 A-u
M2K{{pGJ[&
//保存下载信息（文件指针位置） :%[=v(G[
private void write_nPos() q=NI}k
{ 9"KO!w
try{ hf6=`M}>i
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~r<@`[-L
output.writeInt(nStartPos.length); x-wIgo+
for(int i=0;i<nStartPos.length;i++) g@IV|C(*0
{ 1 &24:&
// output.writeLong(nPos); YCv)DW;
output.writeLong(fileSplitterFetch.nStartPos); Tr}z&efY
output.writeLong(fileSplitterFetch.nEndPos); 6OBe^/ZRt
} d~i WV6Va
output.close(); Vu @2
} &`#k1t'
catch(IOException e){e.printStackTrace ();} H .F-mm
catch(Exception e){e.printStackTrace ();} zV)(i<Q
} W'aZw9
UKYQ @m
}6;K+INT
//读取保存的下载信息（文件指针位置） q|An
private void read_nPos() 8nt3Sm
{ {M`yYeo
try{ 7Hghn"ol
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "gm[q."n<
int nCount = input.readInt(); C,*3a`/2M^
nStartPos = new long[nCount]; HGuU6@~hu
nEndPos = new long[nCount]; ~d0:>8zQR
for(int i=0;i<nStartPos.length;i++) OT1
{ ~UrKyA
nStartPos = input.readLong(); 9YpgzCx Z
nEndPos = input.readLong(); bW"bkA80
} Wo&WO e
input.close(); 2nNBX2o&_
} 8*nv+
catch(IOException e){e.printStackTrace ();} jZjWz1+
catch(Exception e){e.printStackTrace ();} o!R.QI^2VT
} r]e1a\)r
Ban@$uf
yyp0GV.x
private void processErrorCode(int nErrorCode) xJG&vOf;?
{ -^1}J
System.err.println("Error Code : " + nErrorCode); 9CBKU4JQ
} r7Vt,{4/
w}8 ,ICL
tcDWx:Q
//停止文件下载 9v\x&h
public void siteStop() vY 0EffZ
{ i D6f/|g
bStop = true; -L4fp
for(int i=0;i<nStartPos.length;i++) (`W_ -PI
fileSplitterFetch.splitterStop(); 7a$K@iWU
j6!C/UgQ
xwuGJ
} [ B{F(~O
} #7 )&`
//负责部分文件的抓取 6MCLm.L
**FileSplitterFetch.java ///
*/ \,UpFuU\
package NetFox; {Ad4H[]|]
AnF"+<
Sb2hM~
import java.io.*; ;jgk53lo
import java.net.*; UL{+mp
0+-"9pED>E
1c5+XCr
public class FileSplitterFetch extends Thread { ae%Bl[
OC?a[^hB^)
?;GbK2\bj
String sURL; //File URL YC!IIE_
long nStartPos; //File Snippet Start Position .<m${yU{3
long nEndPos; //File Snippet End Position _GhP{C$
int nThreadID; //Thread's ID |IcA8[
boolean bDownOver = false; //Downing is over 0oNNEC
boolean bStop = false; //Stop identical L3/SIoqd
FileAccessI fileAccessI = null; //File Access interface ^}w@&Bje
v3p0
*F<Ar\f5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (Q]Ww_r~
{ |wxAdPe
this.sURL = sURL; Abw=x4d(i
this.nStartPos = nStart; V4#bW
this.nEndPos = nEnd; G '1K6
nThreadID = id; 3_DwqZ 'O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -dto46X
} ;JuBybJb
MG}rvzn@
V=i/cI\
public void run() D`Cy]j
{ GhJ<L3
while(nStartPos < nEndPos && !bStop) Y>J$OA:
{ q1a*6*YB
{4F=].!
QZh#&Qf;
try{ e2"<3
URL url = new URL(sURL); z|M+ FHl$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vVbBg; {
httpConnection.setRequestProperty("User-Agent","NetFox"); .](~dVp%~
String sProperty = "bytes="+nStartPos+"-"; @u>:(9bp
httpConnection.setRequestProperty("RANGE",sProperty); gzMp&J
Utility.log(sProperty); |e QwI&
KgH_-REN
1 $m[#3
InputStream input = httpConnection.getInputStream(); +L\Dh.Ir
//logResponseHead(httpConnection); 3(oB[9]s
@<TC+M5!
QmKEl|/{u
byte[] b = new byte[1024]; nk*T x
int nRead; kEYkd@{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _:1s7EC
{ tLE7s_^
nStartPos += fileAccessI.write(b,0,nRead); g`Kh&|GU
//if(nThreadID == 1) 1 u~Xk?
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [mcER4]}
} ;RW0Dn)Q
I^GZ9@UE
qNuBK6E#4
Utility.log("Thread " + nThreadID + " is over!"); I.6 qA *
bDownOver = true; , 3&DA
//nPos = fileAccessI.write (b,0,nRead); #?h-<KQQ
} S'_2o?fs
catch(Exception e){e.printStackTrace ();} TpGnSD
} 6/dP)"a('
} V[;^{,;
u|+Dqe`
|e_'%d&
//打印回应的头信息 `C&@6{L
public void logResponseHead(HttpURLConnection con) PL|ea~/
{ {9XN\v=$"*
for(int i=1;;i++) ?APCDZ^
{ &SW~4{n:
String header=con.getHeaderFieldKey(i); 4T>d%Tt+)
if(header!=null) hnnVp_<]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oFi_ op
Utility.log(header+" : "+con.getHeaderField(header)); D~zk2
else gQYs,
break; e9;5.m
} X/f?=U
} [gIvB<Uv
XY,!vLjL
s$Vz1B
public void splitterStop() ^2`*1el
{ {nj`>
bStop = true; ,UNnz&H+f
} IMSLHwZ
#G]g
O%1uBc
} or`D-x)+@
LlcH#L$
$ vBFs]h
/* tx$`1KA
**FileAccess.java b?j\YX[e
*//文件访问(定位，写) P]0/S
package NetFox; aeE~[m
import java.io.*; i<M F8$
YJF|J2u
MmQk@~
public class FileAccessI implements Serializable{ xz-?sD/xe
Sg< B+u\\
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^4C djMF-E
RandomAccessFile oSavedFile; zwJ\F '
long nPos; /[I#3|
J%IKdxa
owzcc-g
public FileAccessI() throws IOException R9-Uoc/
{ 5i-VnG
this("",0); .wPI%5D
} &<EixDi4q
1oI2
{ceY:49
public FileAccessI(String sName,long nPos) throws IOException BUUc9&f3o
{ Ae* 6&R4
oSavedFile = new RandomAccessFile(sName,"rw"); G4^6o[x
this.nPos = nPos; g*;zVi
oSavedFile.seek(nPos); g~XR#vl$
} ^|(VI0KO
pHKc9VC
YJ}9VY<}1K
public synchronized int write(byte[] b,int nStart,int nLen) C$d b)5-
{ _ZE&W
int n = -1; ZU;nXqjc
try{ _2WW0
oSavedFile.write(b,nStart,nLen); ujr"_ofI
n = nLen; lv#L+}T
} y\=^pla
catch(IOException e) eyy%2>b
{ <=!FB8 .
e.printStackTrace (); Q[9W{l+
} 24k;.o
A&{eC C
\F14]`i
return n; 9?uU%9r5P
} jd.w7.8
r`sG!
s=Xg6D
} -0+h&CO
BD [<>Wm
C3KAQU
/* ]f6,4[
**SiteInfoBean.java [*g'Y;W
*/ H-3*},9
package NetFox; usw(]CnH
!O4)YM
TiKfIv
public class SiteInfoBean { w& )ApfL
4veXg/l
L0*f(H
private String sSiteURL; //Site's URL ++BQ==@
private String sFilePath; //Saved File's Path 2p~G][
private String sFileName; //Saved File's Name ^*F'[!. p
private int nSplitter; //Count of Splited Downloading File zqLOwzMlLx
{[bB$~7Eu
v7<r-<I[
public SiteInfoBean() p3qKtMs0!
{//nSplitter的缺省值为5 g6@^n$Y
//default value of nSplitter is 5 'jYKfq~_cJ
this("","","",5); e\}'i-
} @=K*gbq5
{d%hkbN+{
!.7m4mKzo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #'I<q
{ lt%9Zgr[u
sSiteURL= sURL; Ue=1NnRDkA
sFilePath = sPath; cHJ4[x=
sFileName = sName; Y8/&1s_
this.nSplitter = nSpiltter; u6 4{w,
p+CK+m
!gi3J @
} d!y_N&z|(
{(Ba
e!w#{</8Q
public String getSSiteURL() i<!1s%i}
{ T/tCX[}
return sSiteURL; R#Z m[S
} 6%&DJBU!
a[J_H$6H!
?>mpUH
public void setSSiteURL(String value) cK75Chsu
{ V=E5pB`Pr
sSiteURL = value; j3fq}>=
} B %
AIw~@*T
|5*:ThC[
public String getSFilePath() <W/YC2b
{ :MGIp%3
return sFilePath; =/19 -Y:
} }ok'd=M
[jTZxH<
)Mh5q&ow
public void setSFilePath(String value) {"_V,HmEF+
{ ]:Pkh./
sFilePath = value; 1n#{c5T
} )H{OqZZYD
;pG5zRe
<<&SyP
public String getSFileName() cUwR6I9
{ {<Xl57w-Q
return sFileName; ZFtN~Tg
} h_B nQZ\
Efu/v<
|9mGX9q
public void setSFileName(String value) C^!~WFy
{ k>#-NPU$
sFileName = value; u+ 8wBb5!
} 5yf`3vV|3@
b7HT<$Wg
UZo[]$"Q`
public int getNSplitter() 8< z
{ \j0016;
return nSplitter; nr%P11U\c
} c22L]Sxo
dl+c+w"
O`.IE? h#
public void setNSplitter(int nCount) l?KP/0`
{ $Q`\-
nSplitter = nCount; VW:Voc
} >|hqt8lY
} Agwl2AM5k
Pk^V6-
C+0BV~7J<<
/* c
**Utility.java >t4<2|!(M
*/ *-@@t+3
package NetFox; Pk:b:(4
9)'wgI#
H4BuxM_r
public class Utility { +[#^c3x2
fAD {sg
(n2=.9k!
public Utility() [L?WM>]%
{ VQbKrnX
@Dd3mWKq
1+Bj` ACP
} YGZa##i
*-s':('R
//线程睡眠 &izk$~
public static void sleep(int nSecond) 8zpTCae^=7
{ `'ak/%Krh
try{ $ 3R5p
Thread.sleep(nSecond); xS_tB)C
} ;eP.B/N
catch(Exception e) nDXy$f8
{ Suk;##I
e.printStackTrace (); |q 0iX2W
} qO>A6
} vcSb:('
MwWN;_#EO)
//日志 NZuylQ)0
public static void log(String sMsg) ":L d}~>
{ Ar`U/ %Cu
System.err.println(sMsg); BsYJIKfW
} s+a#x(7{
tS[@?qP
1pTQMf a
public static void log(int sMsg) J!iKW
{ 8-)@q|
System.err.println(sMsg); }QJ6"s
} sDXQ{*6a
} D#11 N^-K
|k)Nf+(}W
k'K 1zUBj
/* }Q_ }c9?
**TestMethod.java ;uqi
*/ - S%8
package NetFox; {?]&P
l6-%)6u>
j8?rMD~
public class TestMethod { Ki%RSW(_`
OZno 3Hn
xOc&n0}%
public TestMethod() DC=XPn/V
{ ///xx/weblogic60b2_win.exe &DWSu`z
try{ C 4\Q8uK
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CoM?cS S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9j$J}=y
SiteFileFetch fileFetch = new SiteFileFetch(bean); {Lvta4}7(
fileFetch.start(); D__*?frWpW
} {y|j**NZ
catch(Exception e){e.printStackTrace ();} n)rSgzI
G\ /L.T
trL8oZ6
} Pol c.
"XKd#ncP
kj!mgu#T
public static void main(String[] args) nPjN\Es6
{ <nF1f(ky
new TestMethod(); &=laZxe
} UvVq#<-
} f/g-b]0
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