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)); &~Q ?k
} JPk3T.qp
for(int i=0;i<nEndPos.length-1;i++) C6eon4Ut
{ .0q %A1H
nEndPos = nStartPos[i+1]; [J+K4o8L<A
} "t"=9:_t
nEndPos[nEndPos.length-1] = nFileLength; L$x/T3@
} .n`MPx'
} k>Qr14F
pDlh^?cux
7j&l2Z
//启动子线程 <_H0Q_/(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; T+2I:W%
for(int i=0;i<nStartPos.length;i++) )[)-.{q
{ 4f"a/(>*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]IJ.}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b,G+=&6u
nStartPos,nEndPos,i); Bd"7F{H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6|LDb"Rvy
fileSplitterFetch.start(); zq]V6.]J
} b\?#O}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,Ql3RO,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); N[ArwV2O
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v.v3HB8p
nEndPos = " + nFileLength); n@g[VR2t
// fileSplitterFetch[nPos.length-1].start(); W^&t8d2
U'.>wjO
fp4d?3G
//等待子线程结束 Q;5'I3w
//int count = 0; k<W]VS3N
//是否结束while循环 ( L RX
boolean breakWhile = false; gpr];lgS
Dl/UZ@8pl
p9_45u`u2
while(!bStop) ASy7")5
{ zAB-kE\)
write_nPos(); k=bv!T_o
Utility.sleep(500); n*iaNaU"'
breakWhile = true; 4'9h^C&
sS(^7GARa
=GM!M@~,Ab
for(int i=0;i<nStartPos.length;i++) 3g2t{%
{ ZLKS4
if(!fileSplitterFetch.bDownOver) <WBGPzVZE
{ YQX>)'
breakWhile = false; +I\bs.84
break; ?67j+)
} |_[mb(<|
} uNhAfZ
if(breakWhile) -3_kS/
break; eB$v'9S8/
OR"ni
[AX).b
//count++; #0Oqw=F
//if(count>4) pdnL~sv
// siteStop(); N'm:V
} PLo.q|%
bJB:]vs$
=AcbX_[
System.err.println("文件下载结束！"); KS(T%mk\
} sQihyq6U;
catch(Exception e){e.printStackTrace ();} YN>#zr+~
} ?QVD)JI*k
Cv$TNkP*
F/EHU?_EI
//获得文件长度 [S</QS!
public long getFileSize() <!OP b(g2
{ p-KuCobz]
int nFileLength = -1; 29Q5s$YD@
try{ R#\8jvv
URL url = new URL(siteInfoBean.getSSiteURL()); n{' [[2U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }.b[az\T
httpConnection.setRequestProperty("User-Agent","NetFox"); H V
6lWO8j^BN
i,yK&*>JJ
int responseCode=httpConnection.getResponseCode(); $V~%$
if(responseCode>=400) Va*Uwy?x/)
{ s9[v_(W
processErrorCode(responseCode); .=@M>TZM
return -2; //-2 represent access is error dqKTF_+VhA
} +Qc^A
& vLX
3?5 ~KxOE(
String sHeader; (J^ Tss
":-)mfgGU
A<.Q&4jb
for(int i=1;;i++) #sqDZ]\B
{ /{kyjf[o&*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *=|i"
//Utility.log(in.readLine()); ^~`8 - TE
sHeader=httpConnection.getHeaderFieldKey(i); Cq(Xa-
if(sHeader!=null) Y6D=tb
{ ryn)
if(sHeader.equals("Content-Length")) =v;-{oN!
{ ZA9']u%EJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W>DpDrO4ml
break; giu~"#0/F
} U.^)|IHW
} h;ShNU
else Bnxzy n
break; ReK@~#hLY
} )7i?8XiSZF
} s*8hN*A/,
catch(IOException e){e.printStackTrace ();} E$ngmm[
catch(Exception e){e.printStackTrace ();} Y\%}VD2k
k Lv_P[I
f`IgfJN
Utility.log(nFileLength); "rKIXy
!<YRocQY
quKD\hL$
return nFileLength; BO9Z"|"
} Zi[)(agAT
_ma4
Iiy:<c
//保存下载信息（文件指针位置） ynDx'Q*N'
private void write_nPos() ,F-tvSc\Q
{ pz$$K?
try{ NqwVsVL
output = new DataOutputStream(new FileOutputStream(tmpFile)); [{{?e6J
output.writeInt(nStartPos.length); KqS2
for(int i=0;i<nStartPos.length;i++) h?ia4t
{ +I Ze`M%n
// output.writeLong(nPos); ~.@fk}'R
output.writeLong(fileSplitterFetch.nStartPos); .nSupTyG
output.writeLong(fileSplitterFetch.nEndPos); Z956S$gS
} Qrt8O7&('
output.close(); iZSSd{jO
} XsG]-Cw
catch(IOException e){e.printStackTrace ();} _L=vK=,
catch(Exception e){e.printStackTrace ();} Ov<3?)ok
} xLD6A5n,[
*xl7;s
,X$Avdc2
//读取保存的下载信息（文件指针位置） 6Ss{+MF|v
private void read_nPos() }agl:~C
{ {//F>5~[
try{ 8uGPyH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ffxk] o&%c
int nCount = input.readInt(); LNN:GD)>
nStartPos = new long[nCount]; oOL3O@)w>
nEndPos = new long[nCount]; Z~,.l
for(int i=0;i<nStartPos.length;i++) kCC9U_dj,
{ =3zn Ta }
nStartPos = input.readLong(); EIYM0vls(
nEndPos = input.readLong(); aW6+Up+G*
} b #^aM
input.close(); 1`}fbX;"m)
} )4`Ml*7x
catch(IOException e){e.printStackTrace ();} <zf+Ii1:,
catch(Exception e){e.printStackTrace ();} y="SzPl
} V%0.%/<#5
rgYuF,BT.
nM; G; T
private void processErrorCode(int nErrorCode) 28)TXRr-
{ b"Mq7&cf
System.err.println("Error Code : " + nErrorCode); #VOjnc/rW
} *M|\B|A.
z8j(SI;3
qE`=^
//停止文件下载 V-cuG.
public void siteStop() #pe{:f?
{ mWusRgj+8
bStop = true; Ad,r(0a LZ
for(int i=0;i<nStartPos.length;i++) qbEj\ b[
fileSplitterFetch.splitterStop(); 9V66~Bf5
Ds G *
`Of wl%G
} \i,cL)HM
} ];I|_fXo%
//负责部分文件的抓取 6|KX8\,A@
**FileSplitterFetch.java +_gT|vlU
*/ p\{+l;`
package NetFox; X]yERaJ,i
lz)"zV
g&Z7h4!\
import java.io.*; Y1 P[^ws
import java.net.*; |g7h#F~
i)2))C
reA8=>b/
public class FileSplitterFetch extends Thread { `oMeR]~
ya{>=
SznE:+
String sURL; //File URL +hg\DqO^M
long nStartPos; //File Snippet Start Position [)3 U])w/
long nEndPos; //File Snippet End Position ?fmt@@]T?
int nThreadID; //Thread's ID |\a:]SlH
boolean bDownOver = false; //Downing is over lkfFAwnc
boolean bStop = false; //Stop identical CJ?gjV6
FileAccessI fileAccessI = null; //File Access interface m"G N^V7
"k-ov9yK
\B2d(=~4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O^}v/}d
{ |mk}@OEf
this.sURL = sURL; LO]6Xd"
this.nStartPos = nStart; ]|N4 #4
this.nEndPos = nEnd; QklNw6,
nThreadID = id; f%{Tu`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z) Xs;7
} M_1Tx
aEDN]O95?
zcB2[eaV
public void run() b.4Xn0-M
{ \5P.C
while(nStartPos < nEndPos && !bStop) qu~|d}0
{ Fd[h9 G
%?f:"
Yg)V*%0n
try{ M%{?\)s
URL url = new URL(sURL); g`OOVaB
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -(w~LT$ "
httpConnection.setRequestProperty("User-Agent","NetFox"); jBv$^L
String sProperty = "bytes="+nStartPos+"-"; 2 1~7{#
httpConnection.setRequestProperty("RANGE",sProperty); b%;59^4AjD
Utility.log(sProperty); JYd7@Msfc
}[z<iij4
v1r_Z($
InputStream input = httpConnection.getInputStream(); )_v\{N
//logResponseHead(httpConnection); )@qup _M@
*e<Eu>fW#&
fhV0S>*<
byte[] b = new byte[1024]; ^MT9n
int nRead; ChTXvkdH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,iVPcza
{ ]&:b<]K3
nStartPos += fileAccessI.write(b,0,nRead); nnE_OK!}T
//if(nThreadID == 1) FxfL+}?Q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `<J#l;y
} v (ka,Dk3
irsfJUr[V
_;:rkC fj
Utility.log("Thread " + nThreadID + " is over!"); 8rwYNb.P
bDownOver = true; R|1xXDLm*E
//nPos = fileAccessI.write (b,0,nRead); 0HR|aqPo
} ck+b/.gw`
catch(Exception e){e.printStackTrace ();} qon{ g
} tKZ&1E
} `\jTpDV_W
h.V]fS
YN@6}B#1
//打印回应的头信息 ^IGyuj0]jG
public void logResponseHead(HttpURLConnection con) @ EmGexLPM
{ T;!ukGoFP
for(int i=1;;i++) ]G0dS Fh{j
{ '_qQrP#
String header=con.getHeaderFieldKey(i); #+"4&:my
if(header!=null) 85D^@{
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q[G/}
Utility.log(header+" : "+con.getHeaderField(header)); #%^\\|'z
else (`6%og#8
break; B:-U`CHHQ
} ] *-;' *
} mP pvZ
@H\pipT_b
tqf&N0*
public void splitterStop() 0||"r&:X
{ dC`tN5
bStop = true; _1sMYhI
} L)F1NuR
]4Y/xi-
!:"-:O}>=,
} SY,I>-%
yI8m%g%
o\ngR\>
/* xQJIM.
**FileAccess.java VLsh=v
*//文件访问(定位，写) XDk'2ycv
package NetFox; H&X:!xa5
import java.io.*; s=d+GMa
{l2N&
84=-Lw
public class FileAccessI implements Serializable{ )O3jQ_q=
QjA&IZEC
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 b~_B [cf
RandomAccessFile oSavedFile; }:`5,b%Y_
long nPos; V+lRi"m?|
1^C|k(t
5YiZ-CQ>
public FileAccessI() throws IOException [pii
{ 2sKG(^=Z
this("",0); .^i<xY
} :l+_ja&o
z%V*K
DVI7]+=nV
public FileAccessI(String sName,long nPos) throws IOException ITyzs4"VV
{ XHsd-
oSavedFile = new RandomAccessFile(sName,"rw"); }^"0T-ua
this.nPos = nPos; 1SW4Y
oSavedFile.seek(nPos); naz:A
} ^7uX$
Kax#OYLpg
K@HQrv<
public synchronized int write(byte[] b,int nStart,int nLen) \a\= gn
{ JO2xT#V
int n = -1; `=79i$,,t
try{ -!cIesK;<
oSavedFile.write(b,nStart,nLen); !!FR[NK
n = nLen; 9\v.qo.
} ~m=$VDWm
catch(IOException e) Z>8eD|m%2
{ "B#Y-
e.printStackTrace (); A 4j<\xL
} 3gpo %
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bGN 54{f
return n; OX+hZ<y
} 6lsL^]7
*>k!hq;j
$A`xhh[
} !.EcP=S
)1f+ld%R
o/cr{>"N
/* c3] C:t+
**SiteInfoBean.java XLm@etf
*/ I}+;ME|<2
package NetFox; $jG4pPG
b3\B8:XFo|
(/K5!qh
public class SiteInfoBean { D`Gt
^agj4$
H`-=?t
private String sSiteURL; //Site's URL WL l_'2h
private String sFilePath; //Saved File's Path gg[9u-
private String sFileName; //Saved File's Name D`VFf\7
private int nSplitter; //Count of Splited Downloading File Vclr2]eV4O
%cX"#+e
>,"sHm}l%
public SiteInfoBean() ,=|4:F9
{//nSplitter的缺省值为5 ` W4dx&
//default value of nSplitter is 5 )11W)G`w
this("","","",5); B'}"AC"
} KiAcA]0
O8lFx_N7Q
)iU^&@[S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) FXahZW~Ol
{ Uoji@
sSiteURL= sURL; s<vs:jna
sFilePath = sPath; sTkkM9
sFileName = sName; /L&M,OUcr.
this.nSplitter = nSpiltter; cy|%sf`
SfW}"#L>5
L-\ =J
} Mvb':/M
)KY:m |Z
g9KTn4
public String getSSiteURL() yNa;\UF
{ ffE#^|
return sSiteURL; GK?4@<fY
} .9h)bf+
t> . Fl-
z/7$NxJH
public void setSSiteURL(String value) 3;_ n{&
{ -(#-I$z
sSiteURL = value; mS%4gx~~_n
} lb~E0U`\E`
iW;i!,
3c#s|qW
public String getSFilePath() XErUS80
{ ?Elg?)os
return sFilePath; V8PLFt;
} "DQ'C%sL9
^Ga&}-
%=Tr^{i
public void setSFilePath(String value) ;..o7I
{ 8W+5)m.tp
sFilePath = value; 2) ?q58
} t-7og;^8k
p[v#EyoC
9(,@aZ
public String getSFileName() sx 9uV
{ ~R]35Cp-#
return sFileName; gfy19c 9
} g"hJ{{<
B4g8 ~f
Br5o7(AE
public void setSFileName(String value) ,^$|R32
{ ,gx)w^WTm
sFileName = value; 3[IJhR[
} #0"~G][#
+(?>-3_z
U \oy8FZ
public int getNSplitter() kV&9`c+
{ aeP[+I9
return nSplitter; cpZc9;@IC
} S%mfs!E>
jz'<
6bO~/mpWT~
public void setNSplitter(int nCount) a~]bD
{ x_MJJ(q8g
nSplitter = nCount; CN&
} *>q/WLR
} sZhMa>
aFj.i8+
4n0xE[-
/* /)>S<X
**Utility.java cYNV\b4-
*/ lr@#^
package NetFox; 8g~EL{'
q]% T:A=
/rc%O*R
public class Utility { $m| V :/
v;EQ, NL
<a^Oj LLU
public Utility() BR5BJX
{ [A2`]CE<@
(Ddp|a"b
.12aUXo(
} </"4 zD|
$_;e>*+x
//线程睡眠 sLL7]m}
public static void sleep(int nSecond) /JJw 6[N
{ n,'OiVl[
try{ h9s >LY
Thread.sleep(nSecond); FMw&(
} hJ;$A*Y
catch(Exception e) B 0ee?VC
{ Wp0 Dq(
e.printStackTrace (); ]j<Bo4~Il
} 39i9wrP
} ^jE8+h
W"q@Qa`Bm
//日志 *OjKcs
public static void log(String sMsg) An`3Ex[
{ P9Q~r<7n
System.err.println(sMsg); !CTxVLl"F
} J([s5:.[
Z|lU8`'5
s1N?/>lmB
public static void log(int sMsg) t= #&fSR
{ =EP13J
System.err.println(sMsg); K=::)/{P
} U(>4s]O6
} 6IcNZ!j98
cre;P5^E
J3RB]O_
/* <O<LYN+(
**TestMethod.java hfWFD,
*/ `>C<}xO
package NetFox; Jju#iwb
r=uN9ro
o{qr!*_3
public class TestMethod { [Nm4sI11
g|X;ahTT
friWW^
public TestMethod() 1c4/}3*
{ ///xx/weblogic60b2_win.exe DOS0;^f
try{ 0|4%4Mt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [lzN !!B!
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d*8 $>GA
SiteFileFetch fileFetch = new SiteFileFetch(bean); <xpph t<
fileFetch.start(); mEG6
} S[3iA~)Z-
catch(Exception e){e.printStackTrace ();} XN=67f$Hw
&)wiKh"$
I=)hWC/
} 2&mGT&HAVA
6RO(]5wX
C$h<Wt=<
public static void main(String[] args) yOU(2"8p
{ |077Sf|
new TestMethod(); 3rW|kkn
} 'NjzgZ~]P
} 7,qYV}
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