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)); %ZT@&
} 8_yhV{
for(int i=0;i<nEndPos.length-1;i++) W dM?{; #
{ v(5zSo
nEndPos = nStartPos[i+1]; ^! ?wh
} ma__LWKM,
nEndPos[nEndPos.length-1] = nFileLength; b#XY.+ *0
} WX@a2c.'
} v?\Z4Z|f
NJ6* 7Cd
Ct-^-XD
//启动子线程 :Kc9k(3&r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8RGU^&
for(int i=0;i<nStartPos.length;i++) JL[xrK0
{ jIpc^iu`,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eiTG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kkvG=
nStartPos,nEndPos,i); [FhFeW>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b/>L}/^PM
fileSplitterFetch.start(); ){~]-VK
} %d3KE|&u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (e,5 b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <d&9`e1Hc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E'_3U5U
nEndPos = " + nFileLength); &w4~0J>v!
// fileSplitterFetch[nPos.length-1].start(); bq+Q$#F2X
{3s=U"\
(RhGBgp
//等待子线程结束 QzV Q}
//int count = 0; VV'K$v3'N8
//是否结束while循环 NT3Ti ?J,
boolean breakWhile = false; tv,Z>&OM
s48 { R4
tQTVP2:Y
while(!bStop) nIWZo ~
{ tCoT-\Q
write_nPos(); [^rMM1^,OB
Utility.sleep(500); (P=q&]l[
breakWhile = true; j>D[iHrH
wtm=
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for(int i=0;i<nStartPos.length;i++) B)^uGSW
{ J 'qhY'te
if(!fileSplitterFetch.bDownOver) o3=2`BvJ
{ 1MVzu7
breakWhile = false; 3rRN~$
break; +;@p'af!9
} f9ziSD#
} P LHiQ:
if(breakWhile) -UTTJnu^
break; h_xHQf&#
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i.~*G8!DM
//count++; fWutB5?P
//if(count>4) #.Q8q
// siteStop(); /*$B
} N^Bjw?3
)p?p39>h
,m"0Bu2
System.err.println("文件下载结束！"); #KFpT__F
} 5:"zs
catch(Exception e){e.printStackTrace ();} @'D ,T^I
} -D?-ctFYj^
CVa?L"lK
VZo,AP~
//获得文件长度 U/p|X)
public long getFileSize() ke~S[bL%-
{ W.|r=
int nFileLength = -1; p K=
try{ zJxO\
URL url = new URL(siteInfoBean.getSSiteURL()); &@&0n)VTd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |mHxkd
httpConnection.setRequestProperty("User-Agent","NetFox"); X3# AYn,
G/y@`A)
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int responseCode=httpConnection.getResponseCode(); @U)k~z2Hk
if(responseCode>=400) jE.yT(+lW
{ @+iO0?f
processErrorCode(responseCode); v +$3Z5
return -2; //-2 represent access is error :<"b"{X"
} 62YT)/i3
q-k~L\Ys
}\-"L/D?+
String sHeader; w%Bo7 'o)V
I7[F,xci
JsDugn ,B
for(int i=1;;i++) MhaoD5*9
{ c;M&;'#x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Pl9Ky(Q`V
//Utility.log(in.readLine()); "{1SDbwmMo
sHeader=httpConnection.getHeaderFieldKey(i); Ho_ 2zx:8b
if(sHeader!=null) Z` ;.62S
{ 6Z:swgi6&
if(sHeader.equals("Content-Length")) s\Zp/-Q
{ :)PAj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L2NO_N
break; +^@;J?O
} cW|M4`
} cD!yd^QE
else [0lu&ak[&
break; @/DHfs4O
} Q+r8qnL'
} .5ItH^
catch(IOException e){e.printStackTrace ();} eG F{.]
catch(Exception e){e.printStackTrace ();} 0}:wM':G
u`j9m@`
8B|qNf `Yi
Utility.log(nFileLength); eHt |O~
uFXu9f+
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return nFileLength; /-mo8]J#2~
} `g~T #U\>d
!.^%*6f
~"t33U6
//保存下载信息（文件指针位置） s .xJ},E9
private void write_nPos() L<`p;?
{ ;OTd<
try{ 3WTNWz#h
output = new DataOutputStream(new FileOutputStream(tmpFile)); {,Py%.vvR
output.writeInt(nStartPos.length); 0>aAI3E
for(int i=0;i<nStartPos.length;i++) lY,dyNFHV
{ en1NFP
// output.writeLong(nPos); x9lG$0k:V
output.writeLong(fileSplitterFetch.nStartPos); n}T;q1
output.writeLong(fileSplitterFetch.nEndPos); =Eimbk
} 3r]m8Hp
output.close(); 8}A+{xVp8
} %YhM?jMW
catch(IOException e){e.printStackTrace ();} 0IP5&[-P
catch(Exception e){e.printStackTrace ();} *fIb|r
} *It`<F|
R{X@@t9@
tsqkV7?
//读取保存的下载信息（文件指针位置） XXe?@w2{
private void read_nPos() FVw4BUOmi
{ :v(fgS2\
try{ -9(9LU2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0~;Owu
int nCount = input.readInt(); VD).UdUn
nStartPos = new long[nCount]; WF!u2E+
nEndPos = new long[nCount]; yM}Wg~:D:
for(int i=0;i<nStartPos.length;i++) /3>5ex>PN
{ ]'%Z&1 w
nStartPos = input.readLong(); iFi6,V*PRt
nEndPos = input.readLong(); /xu#ZZ?8F_
} 1X7tN2tQ
input.close(); -*QxZiKD
} th 9I]g^=t
catch(IOException e){e.printStackTrace ();} g`690
catch(Exception e){e.printStackTrace ();} ~dpU DF
} 7w_cKR1;
lJR
T`?{Is['(
private void processErrorCode(int nErrorCode) a7_&;
{ ZtFOIb*
System.err.println("Error Code : " + nErrorCode); 6')pM&`t
} ;@&mR<5j
TS~>9h\;
b_p/ 1W:
//停止文件下载 yN4K^#
public void siteStop() Uql|32j
{ U11bQ4ak
bStop = true; r*gQGvc
for(int i=0;i<nStartPos.length;i++) (/oHj^>3N`
fileSplitterFetch.splitterStop(); y!,Ly_x$@
O6gl[aZN
%( tu<
} 2L!wbeTb;
} c[h{C!d1
//负责部分文件的抓取 DviRD[+q"
**FileSplitterFetch.java ;#goC N.
*/ 3a_=e B
package NetFox; Rb8wq.LqD
:|P[u+v
tt=JvI9>
import java.io.*; j-% vLL/
import java.net.*; :zWI"
>&mNC\PA
$}*bZ~
public class FileSplitterFetch extends Thread { Hfw*\=p
Ac'0
e{*-_j"I
String sURL; //File URL =gYKAr^p5
long nStartPos; //File Snippet Start Position YH 5jvvOI
long nEndPos; //File Snippet End Position cKbjW
int nThreadID; //Thread's ID n&4 4Acs[
boolean bDownOver = false; //Downing is over oQ=v:P]
boolean bStop = false; //Stop identical ^Qx qv
FileAccessI fileAccessI = null; //File Access interface ."u-5r<O
{4%B^+}T
LMF@-j%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )rqb<O
{ tcm?qro)
this.sURL = sURL; $0f(Gc|
this.nStartPos = nStart; ^^O @ [_
this.nEndPos = nEnd; 5Wyo!pRi
nThreadID = id; zHEH?xZ6sD
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "Q>gQKgL
} LxcC5/@\~(
}#0i1]n$D
\m\E*c ):
public void run() qVvQ9?
{ 6hW ~Q
while(nStartPos < nEndPos && !bStop) VX;br1$X
{ g$(<wWsU
AxsTB9/
,?OWwm&J
try{ fs:%L
URL url = new URL(sURL); - s}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,/XeG`vk
httpConnection.setRequestProperty("User-Agent","NetFox"); s\CZ os&
String sProperty = "bytes="+nStartPos+"-"; A$H;2T5N
httpConnection.setRequestProperty("RANGE",sProperty); Q^|ZoJS
Utility.log(sProperty); I 19 /
S1!X;PP/
z;#DX15Rj
InputStream input = httpConnection.getInputStream(); g ss 3e&
//logResponseHead(httpConnection); L355uaj
TVVr<r
^iHwv*ss
byte[] b = new byte[1024]; 9}=]oX!+V
int nRead; ;F/yS2p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 323zR*\m
{ cg]\R1Gm
nStartPos += fileAccessI.write(b,0,nRead); n.323tNY
//if(nThreadID == 1) " 0:&x n8L
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T&ECGF;Y/
} >Z\{P8@k0
8n[6BF);
whA
Utility.log("Thread " + nThreadID + " is over!"); EGY'a*]cU
bDownOver = true; G~ldU: ?
//nPos = fileAccessI.write (b,0,nRead); Q7~9~
} w,,QXJe{Z_
catch(Exception e){e.printStackTrace ();} /CE]7m,7~K
} vq.~8c1
} _N-.=86*
C,;hNg[
06Irx^n
//打印回应的头信息 t=K;/1
public void logResponseHead(HttpURLConnection con) }^}fx [
{ #TXN\YNP
for(int i=1;;i++) v}Gpw6
{ 1&Fty'p
String header=con.getHeaderFieldKey(i); 4GiHp7Y&A
if(header!=null) sp2"c"_+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :FUefW m
Utility.log(header+" : "+con.getHeaderField(header)); }Sxuc/%:
else BJ c'4>
break; {Xc^-A[~
} FRSz3^Aw
} iPD5 KsAOA
&?#,rEw<x
mr4W2Z@L
public void splitterStop() lJ'.1Z&
{ Q?Y\WD
bStop = true; 2i~tzo
} =)2sehU/
\e=Iw"yd
nO^m
} R.Plfm06Ue
<3 b|Sk:T
wfecM(
/* 7M|!N_ $
**FileAccess.java $RFy9(>
*//文件访问(定位，写) DR d|m<Z
package NetFox; 5`!Bj0Uf
import java.io.*; ^tw\F7
3!&PI
yR`X3.:*]
public class FileAccessI implements Serializable{ 9L`5r$/
c"pI+Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F7FUoew<
RandomAccessFile oSavedFile; ]YO &_#
long nPos; ]ZkR~?
<~%e{F:[#
,C=Lu9
public FileAccessI() throws IOException e(5:XHe
{ :jJ;&t^^
this("",0); #[Z1W8e
} (P+TOu-y\
CJDnHuozc
jo7`DDb
public FileAccessI(String sName,long nPos) throws IOException S\,~6]^T
{ %gd{u\h^
oSavedFile = new RandomAccessFile(sName,"rw"); jGeil qPC
this.nPos = nPos; a5)<roWQ
oSavedFile.seek(nPos); up# R9 d|
} \),DW)
CQ4MQ<BJ.
#:~MtV
public synchronized int write(byte[] b,int nStart,int nLen) '=M4(h
{ I3ZlKI
int n = -1; %![%wI?
try{ N=JZtf/i
oSavedFile.write(b,nStart,nLen); -L.U4x
n = nLen; ![>j`i
} *2?-6
catch(IOException e) CTNeh%K;
{ dGNg[
e.printStackTrace (); 2"'<Yk9
} E1=WH-iA0
xw>\6VNt
oHW:s96e
return n; FLb Q#c\
} ~]d3 f
||}k99y +
3pV^Oe^9
} o_(@v2G`
{\SJr:
+9tm9<F8
/* &=KNKE`
**SiteInfoBean.java Hv>16W$_
*/ *-zOQ=Y
package NetFox; ".Z1CBM(
<kmH^viX
(=T%eJ61
public class SiteInfoBean { KKCzq |
{mkD{2)KQ
,?3)L
private String sSiteURL; //Site's URL }.L\O]~{
private String sFilePath; //Saved File's Path h@^d Vg
private String sFileName; //Saved File's Name K[.*8
private int nSplitter; //Count of Splited Downloading File o>#ue<Bc6
"B$r{ vG
,4OH9-Q1
public SiteInfoBean() ]"*sp
{//nSplitter的缺省值为5 "1-gMob
//default value of nSplitter is 5 (]Pr[xB
this("","","",5); ++m^z` D
} lCX*Q{s22
77]6_
HW@r1[Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )Rlh[Y& r
{ 3YFbT Z
sSiteURL= sURL; ^z _m<&r
sFilePath = sPath; #},4m
sFileName = sName; kT=KxS{
this.nSplitter = nSpiltter; 1luRTI8^
[yEH!7
8+?|4'\`
} ~vL`[JiK
)~Pj3
TTfU(w%&P
public String getSSiteURL() W/\M9
{ W`d\A3v
return sSiteURL; IHrG!owf
} Gy3t
Y\e8oIYu7
HgY>M`U
public void setSSiteURL(String value) m|c5X)}-
{ b}C6/zW
sSiteURL = value; : U Yn
} =8p *Ijs
m,qMRcDF
,~TV/l<
public String getSFilePath() G|LJOq7QB
{ n{@^ne4m
return sFilePath; U.kTdNSp
} v=Y) A?
U7(t >/
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public void setSFilePath(String value) >X$I:M<L
{ ^=1:!'*3D
sFilePath = value; ,5 A&
} Vi5&%/Y
4kr! Af
*.2[bQL@v
public String getSFileName() rmq^P;At
{ ]rY3bG'&
return sFileName; zfBaB0P
} `Cv@16
"(QI7:iM
tnn,lWu|
public void setSFileName(String value) zNo(|;19
{ ,xzSFs>2
sFileName = value; KsG>,# Q
} s7(I
,RYahu
Li{R?Osx
public int getNSplitter() 8K;wX%_,
{ h88IP:bo
return nSplitter; Y;B#_}yF
} Cr;d !=
8A,="YIt
t)62_nu
public void setNSplitter(int nCount) l`' lqnhv
{ /iwL$xQQ
nSplitter = nCount; -|/kg7IO\
} NA<6s]Cs.
} % njcWVP;
n?EL\B
@0qDhv s
/* |Ox!tvyr
**Utility.java "KhVS
*/ c8=@s#
package NetFox; =I6u*$9<
M?FbBJ`sF
`BGU
public class Utility { a=%QckR*
n~e#Y<IP\1
:{tj5P!S
public Utility() g218%i
{ BGSqfr1F
M%#H>X\/
|TE\]
} iJsa;|2/
LqOjVQxz
//线程睡眠 OD~TWT_
public static void sleep(int nSecond) wRLj>nc
{ ` g5S
try{ mm@)uV<\
Thread.sleep(nSecond); zr1,A#BV
} uV'w0`$y
catch(Exception e) <Ky6|&!
{ Ou'<9m!9
e.printStackTrace (); 9>1 $Jv3
} `tjH#W`
} DdG*eKC
ROfr
//日志 wsg u# as|
public static void log(String sMsg) G1`H H&
{ F87aIJ.pGN
System.err.println(sMsg); wwI'n*Q'$
} }ippi6b:r
h4 X>
H>/LC* 8-
public static void log(int sMsg) MY$-D+#/`
{ U(t_uc5q
System.err.println(sMsg); rdY/QvP0=
} g'Id31r'
} F#az&
5uJ{#Zd
Ov5*&*P
/* -Z/'kYj?U
**TestMethod.java 6d%|yl
*/ ~5xs$ub
package NetFox; 6?X)'
ue~?xmZg
Jjgy;*hM
public class TestMethod { N!hS`<}
G;CB%qXI
F]"Hs>
public TestMethod() HxXCxI3
{ ///xx/weblogic60b2_win.exe nP+]WUnY
try{ zs_^m1t1s
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,aLdW,<6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0k7kmDW
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~=pAy>oV
fileFetch.start(); #!n"),3
} +mqz)-x
catch(Exception e){e.printStackTrace ();} 5{@Hpj/B
xr<.r4
K#LG7faj
} RlH~<|XK
nLfITr|5
]rs7%$ZW
public static void main(String[] args) H|K}m,g
{ =%Yw;%0)Y
new TestMethod(); yN Bb(!u
} -UhGacw
} IRxFcLk
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