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)); t~nW&]E
} %+;l|Z{Uf
for(int i=0;i<nEndPos.length-1;i++) 5,V*aP
{ "r3h+(5
nEndPos = nStartPos[i+1]; 3bjCa\ "
} 2Vu?Y
nEndPos[nEndPos.length-1] = nFileLength; 9 `q(_\x
} m\bmBK"I
} H{Lt,#
f5l\3oL
[p}~M-$V8Y
//启动子线程 e"XolM0IM
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wm5[+z|2?9
for(int i=0;i<nStartPos.length;i++) </?ef&
{ *M0O&"~j
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m({q<&]Qp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), q;IuV&B
nStartPos,nEndPos,i); CdPQhv)m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D%c^j9' 1
fileSplitterFetch.start(); UQ7La 7"
} n<<arO"cv
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?~#[cx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z7[S698
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", J^%E$s
nEndPos = " + nFileLength); ^Jdg%U?
// fileSplitterFetch[nPos.length-1].start(); ,j\uvi(Y
v0tFU!Q%
dLwP7#r
//等待子线程结束 8*&73cp
//int count = 0; ) LTV+?
//是否结束while循环 l @@pXg3
boolean breakWhile = false; ^P/OHuDL
w}t}Sh
mqUDve(
while(!bStop) Fi\)ka\u
{ |ITb1O`_P
write_nPos(); @~N"MsF3
Utility.sleep(500); gTB|IcOs
breakWhile = true; ;X0uA?
;:ZD<'+N
qQO*:_ezzk
for(int i=0;i<nStartPos.length;i++) \F\7*=xk
{ D!Nc&|X^
if(!fileSplitterFetch.bDownOver) .h4Z\R`
{ v)nv"o[
breakWhile = false; {#`wW`U^
break; LmJ _$?o
} #UI`+2w
} Yl$@/xAa
if(breakWhile) l[m*csDk"
break; j \d)#+;
Zy:q)'D=
K V?+9qa,
//count++; @Gw]cm
//if(count>4) O&~ @ior
// siteStop(); nmE H/a
} QQS"K g
yv>uzb`N
f;l}Z|dok6
System.err.println("文件下载结束！"); wN/v-^2
} DAORfFG74
catch(Exception e){e.printStackTrace ();} u(?U[pe[
} A=e1uBGA
k]RQ 7e
7v0VZ(UR
//获得文件长度 I69Z'}+qz
public long getFileSize() XtBEVqrhi
{ R"CF xo
int nFileLength = -1; `zl,|}u)
try{ g}a+%Obb
URL url = new URL(siteInfoBean.getSSiteURL()); OPqhdqo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]iFW>N*a
httpConnection.setRequestProperty("User-Agent","NetFox"); D@[#7:rHL
-HuIz6
HJpx,NU'
int responseCode=httpConnection.getResponseCode(); (dO0`wfM
if(responseCode>=400) V|HO*HiB3
{ (I>SqM Y
processErrorCode(responseCode); |o(te
return -2; //-2 represent access is error f.oY:3h:
} xUa9>=JU{
UCFFF%
';D>Z?l
String sHeader; aYHs35
}S13]Kk?=
1Ak0A6E
for(int i=1;;i++) een62-`
{ ^(7l!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rd[mC[ r
//Utility.log(in.readLine()); ];g~)z
sHeader=httpConnection.getHeaderFieldKey(i); {CVZ7tU7]
if(sHeader!=null) C$LRX7Z`o
{ X9^q-3&60
if(sHeader.equals("Content-Length")) bmKvvq
{ k][{4~z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); r8czDc),b
break; ybv< 1
} n%~r^C_
} $ >].;y?$
else QAZs1;lU
break; ]2iIk=r$
} 3!#FG0Z
} 55y{9.n*
catch(IOException e){e.printStackTrace ();} -JFW ,8=8
catch(Exception e){e.printStackTrace ();} q9InO]s&~=
<&)zT#"
Pmr'W\aIR
Utility.log(nFileLength); '9<8<d7?
r4K%dx-t
ATmyoN2@>
return nFileLength; ,5 3`t
} j0Os]a
]lE5^<<
aSHN*tP%y
//保存下载信息（文件指针位置） uz=9L<$
private void write_nPos() B/hQvA;(
{ ?A*<Z%}1?
try{ A4;~+L:M
output = new DataOutputStream(new FileOutputStream(tmpFile)); )2Y]A^Y
output.writeInt(nStartPos.length); @KZW*-"
for(int i=0;i<nStartPos.length;i++) EF=5[$ u
{ < mFUT
// output.writeLong(nPos); 7nW <kA
output.writeLong(fileSplitterFetch.nStartPos); ^d(gC%+!u
output.writeLong(fileSplitterFetch.nEndPos); .O+,1&D5
} &/otoAr(
output.close(); _ph1( !H$
} nU#K=e =W
catch(IOException e){e.printStackTrace ();} Gs04)KJm<
catch(Exception e){e.printStackTrace ();} $h=v;1"
} vJx( lU`Y
(gcy3BX;
|&bucG=
//读取保存的下载信息（文件指针位置） WBzPSnS2
private void read_nPos() l%yQ{loTh
{ jrttWT
try{ +#X+QG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9]/:B8k
int nCount = input.readInt(); >29c[O"[
nStartPos = new long[nCount]; F^}d>2W(
nEndPos = new long[nCount]; L}g#h+GP[
for(int i=0;i<nStartPos.length;i++) wW<u)|>ye
{ uX1{K%^<TW
nStartPos = input.readLong(); ,eqRI>,\
nEndPos = input.readLong(); X?`mYoe
} M%SNq|Lo
input.close(); %Z*)<[cIE0
} KXWz(L!1
catch(IOException e){e.printStackTrace ();} v`6vc)>8
catch(Exception e){e.printStackTrace ();} !l6ht{
} Un5 AStG
0+w(cf~6
yaHkWkl =
private void processErrorCode(int nErrorCode) '?X?'_3
{ >+:cTQ|q
System.err.println("Error Code : " + nErrorCode); ##1/{9ywy
} MdTu722
xz+;1JAL3
X@)'E9g5:
//停止文件下载 ~1S,[5u|s
public void siteStop() F hyY+{%
{ mFd|JbW
bStop = true; 5,Co(K
for(int i=0;i<nStartPos.length;i++) jz\>VYi(7
fileSplitterFetch.splitterStop(); 6hXh;-U
6_g6e2F
{e., $'#
} `sd H q
} Vk76cV D
//负责部分文件的抓取 N7;kWQH
**FileSplitterFetch.java @TzUcE
*/ zMO xJ
package NetFox; ]2[\E~^KU
B.gEV*@
;L%\[H>G
import java.io.*; ;9Wimf]G,E
import java.net.*; cBCC/n
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@?0))@kPc3
public class FileSplitterFetch extends Thread { RE]*fRe7#
"|PX5
^Q!A4qOQ
String sURL; //File URL 1ZvXRJ)%
long nStartPos; //File Snippet Start Position h6tYy_(G
long nEndPos; //File Snippet End Position EKmn@S-&P
int nThreadID; //Thread's ID `2q]ju
boolean bDownOver = false; //Downing is over Jl$ X3wE
boolean bStop = false; //Stop identical u|Ng>lU
FileAccessI fileAccessI = null; //File Access interface }|znQ3A2\l
1XHE:0!dQ
i3$pqNe
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N#X* 0i"
{ 0P;LH3sx
this.sURL = sURL; $vnx)#r3
this.nStartPos = nStart; J@ 8OU
this.nEndPos = nEnd; %e+*&Z',
nThreadID = id; ~!/agLwY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Xl>ZnI];
} q$}gQ9'z'
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public void run() C!Fi&~
{ iD>H{1 h
while(nStartPos < nEndPos && !bStop) ._&SS,I5VZ
{ z|$9%uz"
y%<CkgZS
Ejyo oO45
try{ ]Z*B17//
URL url = new URL(sURL); >g{b'Xx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x,GLGGi}_x
httpConnection.setRequestProperty("User-Agent","NetFox"); gYmO4/c,
String sProperty = "bytes="+nStartPos+"-"; ( F4c0
httpConnection.setRequestProperty("RANGE",sProperty); $A T kCO
Utility.log(sProperty); gy"<[N .?c
Cli:;yi&n
|vxmgX)
InputStream input = httpConnection.getInputStream(); Lw<.QMN%f
//logResponseHead(httpConnection); }!m}?
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/.sho\a
byte[] b = new byte[1024]; KD--w(4
int nRead; 4"\%/kG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ZM[Z9/S8
{ WDt6{5T
nStartPos += fileAccessI.write(b,0,nRead); LbR'nG{J
//if(nThreadID == 1) x]t$Zb/Uxa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F;BCSoO4
} =RQI5nHdw
mo&9=TaG
d *#.(C9^
Utility.log("Thread " + nThreadID + " is over!"); \[ 4y
bDownOver = true; %pf9Yd0t
//nPos = fileAccessI.write (b,0,nRead); j@{dsS:6
} !w;/J^
catch(Exception e){e.printStackTrace ();} @R(Op|9
} (ki= s+W-
} wNmC1HOh
Ns5P,[pBOZ
Ep3I*bQ Y
//打印回应的头信息 f85~[3 J
public void logResponseHead(HttpURLConnection con) E5Sn mxd
{ Z_[L5B]Gwd
for(int i=1;;i++) {xh5s<uOj
{ QXgfjo
String header=con.getHeaderFieldKey(i); Zx7aae_{
if(header!=null) @ 'U`a4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Sf@xP.d
Utility.log(header+" : "+con.getHeaderField(header)); zMd><UQP{
else SIc~cZ!Yu
break; :39arq
} 2IGU{&s
} ]bYmM@
XWq"_$&LF
jBl$r{L
public void splitterStop() N7YCg
{ O2"V'(
bStop = true; ,LDL%<7t
} Ge^,hAM'
W>:MK-_J
6~x a^3G:
} aIh} j,
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[jrfh>v
/* M0OIcMTv
**FileAccess.java <FI*A+I4\
*//文件访问(定位，写) NytodVZ'3
package NetFox; m9+?>/R
import java.io.*; 2 )3oX
-eIo
)d2:r 07a
public class FileAccessI implements Serializable{ #^R@EZ
23 #JmR
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]'w5s dP
RandomAccessFile oSavedFile; @u:`
long nPos; 0WYu5|
G?61P[j7
5UG9&:zu'V
public FileAccessI() throws IOException ,KU%"{6
{ fNfa.0s
this("",0); !hHX8TD^J
} axq~56"7E
\fuz`fK:
Z:es7<#y
public FileAccessI(String sName,long nPos) throws IOException [-\U)>MY(p
{ q/d?cLgl
oSavedFile = new RandomAccessFile(sName,"rw"); V>GJO(9
this.nPos = nPos; lyyf&?2
oSavedFile.seek(nPos); J9DI(`
} n&zEYCSI
WWH<s%C
`%"x'B`mM
public synchronized int write(byte[] b,int nStart,int nLen) tE <?L
{ kqxq'Aq)d
int n = -1; 7Z<GlNv
try{ -Fu,oEj{*
oSavedFile.write(b,nStart,nLen); CDsl)
n = nLen; I,HtW),
} FQ`1c[M@
catch(IOException e) vqO#Z
{ 2oRwDg&7|
e.printStackTrace (); PAtv#)h
} z8]@Gh+ (
+"bi]^\z
(E&M[hH+
return n; \Q1&w2mw
} '}B"071)<
?%Tx% dB
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} (2M00J-o
v+`'%E
)pT5"{
/* 3S2Alx!6
**SiteInfoBean.java b4bd^nrqV
*/ N-knhA
package NetFox; r jxkgd
NH}o`x/
_z{9V7n4
public class SiteInfoBean { (xVx|:R[<H
6NhGTLI
g1"ZpD
private String sSiteURL; //Site's URL ;in-)`UC!
private String sFilePath; //Saved File's Path D15-pz|Q
private String sFileName; //Saved File's Name G/~gF7
private int nSplitter; //Count of Splited Downloading File Bp5ra9*5+~
;v2eAe@7
?eX/vqk
public SiteInfoBean() q*` m%3{
{//nSplitter的缺省值为5 LP|YW*i=IQ
//default value of nSplitter is 5 SJMbYjn0J
this("","","",5); C58o="L3S
} -WF((s;<#
S7nx4c2xK~
Pmd[2/][
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HF_8661g
{ Q~svtN
sSiteURL= sURL; FdzdoMY
sFilePath = sPath; &Mudu/KTr
sFileName = sName; Og1vD5a
this.nSplitter = nSpiltter; RJerx:]
0zSz[;A
>c<xy>N
} K[OOI~"C
R2-F@_
3e1-w$z&S
public String getSSiteURL() Uuu2wz3O0
{ :Hm'o}
return sSiteURL; Xo~q}(ze^
} 0+@:f^3]!
QkD ~
0!0e$!8l
public void setSSiteURL(String value) /(hTk&
{ ,f:K)^yD
sSiteURL = value; w(S~}'Sg*P
} _u$DcA8B
?#(LH\$l_
]k7%p>c=B
public String getSFilePath() 37a1O>A
{ z+6PVQ
return sFilePath; A-=hvJ5T
} rM A%By^L-
C`kqsK
tJ>>cFx
public void setSFilePath(String value) _",(!(
{ Q*ELMib
sFilePath = value; w->Y92q]
} , ftJw
s=jYQ5nv
$9Bzq_!
public String getSFileName() i({\fb|0
{ !'F1Ht
return sFileName; YF-E1`+?<
} sfn^R+x4,9
O(8CrKYY
u_9c>
public void setSFileName(String value) ui#nN
{ .Hqq!&
sFileName = value; 5= &2=
} Y8v[kuo7
=wDXlAQ
r.zgLZ}3&V
public int getNSplitter() }Cw,m0KV/
{ f*Q9u>1p
return nSplitter; i^.eX VV/
} `Tyd1!~
M3@qhEf?vk
IA.7If&k
public void setNSplitter(int nCount) [j'!+)>_
{ +z?gf*G_W'
nSplitter = nCount; /Z^a,%1
} 87l*Y|osP
} )/)u.$pi
W#P\hx
[ R+M .5
/* L f"!:]
**Utility.java [y'blCb
*/ N'EZJoH
package NetFox; U-1UWq
!fn%Q'S
H<i!C|AF
public class Utility { !10/M
rmkBp_i{|
K\U`gTGc
public Utility() IMqe(
{ [iq^'E
E#rQJ
vMou`[\WlJ
} ,s3|
6&SNFOX{@
//线程睡眠 zytN leyc
public static void sleep(int nSecond) \z!lw
{ `IwZVz
try{ ~//9Nz~;3
Thread.sleep(nSecond); l%GArH`
} N^[ F+y
catch(Exception e) >VIFQ\
{ /Ls|'2J<$
e.printStackTrace (); k $^/$N
} TU~y;:OJ
} #`|Nm3b
G2I%^.s
//日志 @~ke=w6&pe
public static void log(String sMsg) ~v2(sRJ
{ A)n_ST0
System.err.println(sMsg); 3<$Ek3X
} b; C}=gg
vPYHM2
F6yFKNK!n
public static void log(int sMsg) iU 6,B
{ 8TB|Y
System.err.println(sMsg); \a;xJzc9
} J Y8Rk=
} Q<V1`e
)JTQZ,f3]
RDDA^U7y#
/* >fP;H}S6
**TestMethod.java m\jjj^f a
*/ [nVBnB
package NetFox; w"[T
lJFy(^KQG,
i,;eW&
public class TestMethod { eJ45:]_%I@
(,o@/ -o
!^F_7u@Q
public TestMethod() .gC.T`/m
{ ///xx/weblogic60b2_win.exe 3^ UoK
try{ v?]a tb/h`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1\@PrO35J
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fTR6]i;
SiteFileFetch fileFetch = new SiteFileFetch(bean); ?'f
fileFetch.start(); 2C:u)}R7D
} !YGHJwW:
catch(Exception e){e.printStackTrace ();} N5zWeFq@6
D['J4B
)s:kQ~+
} |0}Xb|+
T\p>wiY2|F
`!N}u
public static void main(String[] args) ? Pi|`W
{ 5%9Uh'y#
new TestMethod(); Go c*ugR
} U{ 0~&
} a"YVr'|
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