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)); 9n& &`r
} v'W{+>.
for(int i=0;i<nEndPos.length-1;i++) Jka>Er
{ Ie.*x'b?y
nEndPos = nStartPos[i+1]; D=0YLQ*rP
} v675C#l(
nEndPos[nEndPos.length-1] = nFileLength; Eomfa:WL
} -s3`mc}*
} K-0=#6?y4
DB/~Z
]r Uj<[O
//启动子线程 @Rr=uf G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \^!;r9z=A
for(int i=0;i<nStartPos.length;i++) :os8"
{ Mog>W&U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *~vB6V|1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %{u@{uG0'3
nStartPos,nEndPos,i); JrzPDb`m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); RM;a]g*
fileSplitterFetch.start(); YuK+N
} PkvW6,lS
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #Rw!a#CX.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aAg Qv*
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >qeDb0
nEndPos = " + nFileLength); F@BpAl
// fileSplitterFetch[nPos.length-1].start(); (95|DCL
lLD#|T3
/ZvP.VW&
//等待子线程结束 O^L]2BVC
//int count = 0; y )QLR<wf
//是否结束while循环 /<rvaR
boolean breakWhile = false; 19E(Hsz
y]db]pP5
)w7vE\n3
while(!bStop) w!F>fcm
{ 6/UOzV,[
write_nPos(); Na0^csPm
Utility.sleep(500); FM{f{2j
breakWhile = true; Hjm> I'9
;_<~9;
Z& _kq|
for(int i=0;i<nStartPos.length;i++) n7t}G'*Y!^
{ m<CrkKfpG
if(!fileSplitterFetch.bDownOver) jPWONz(#
{ IWv 9!lW
breakWhile = false; "Z.6@ c7
break; UqK.b}s
} GcV/_Y
} OSBR2Z;=
if(breakWhile) };Q}C0E
break; 4 &bmt
K=gg<E<
)OI}IWDl
//count++; \e86'&
//if(count>4) 8eXeb|?J
// siteStop(); _Ewh:IM-
} 1eI*.pt
?8~l+m6s$
,rB(WKU
System.err.println("文件下载结束！"); L=lSW7R
} #}7T$Va
catch(Exception e){e.printStackTrace ();} d{fd5jv;
} Ed=/w6<
wB)y@w4k
f^pBXz9&=
//获得文件长度 T+Yv5l
public long getFileSize() Gu$/rb?
{ Wl| i$L)7
int nFileLength = -1; aL(G0@(
try{ aO{@.
URL url = new URL(siteInfoBean.getSSiteURL()); j2G^sj"|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [n"eD4)K|
httpConnection.setRequestProperty("User-Agent","NetFox"); t|U5]$5
@b(@`yz.a
klKUX/g
int responseCode=httpConnection.getResponseCode(); Z_GGH2u
if(responseCode>=400) & AK\Pw)
{ m* 3ipI{h
processErrorCode(responseCode); 4)iP%%JH
return -2; //-2 represent access is error -r*|N.5c
} 0moAmfc
,7V?Kj
L&6^(Bn
String sHeader; 7;Ze>"W>
0MRWx%CR
7rD 8
for(int i=1;;i++) |uy@v6
{ d>[i*u,]/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .]E(P
//Utility.log(in.readLine()); >_j(uw?u
sHeader=httpConnection.getHeaderFieldKey(i); (1x8DVXNN
if(sHeader!=null) +pYgh8w@
{ e6p3!)@P1
if(sHeader.equals("Content-Length")) h1S)B|~8
{ dEYw_qJ2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /)[-5n{
break; $6m@gW]N
} {N]WVp*R
} r(Sh
else u^xnOVE
break; 4- QlIIf
} IhzY7U)}T
} (+gTIcc >
catch(IOException e){e.printStackTrace ();} G+#bO5
catch(Exception e){e.printStackTrace ();} r)~?5d
aNry>2:
8b0j rt
Utility.log(nFileLength); g5U,
ItLR|LO9
@~vg=(ic(
return nFileLength; t{UVX%b
} z:S:[X0
uPl7u1c
+6>2= ,?Z
//保存下载信息（文件指针位置） F4~OsgZ'N
private void write_nPos() l`~$cK!
{ .@x.
try{ 0#GnmH
output = new DataOutputStream(new FileOutputStream(tmpFile)); @|;[ ;:h@
output.writeInt(nStartPos.length); tX% C5k
for(int i=0;i<nStartPos.length;i++) ,Gy,bcv{
{ H,<CR9@(5d
// output.writeLong(nPos); 47Vt8oyh%
output.writeLong(fileSplitterFetch.nStartPos); +|;Ri68
output.writeLong(fileSplitterFetch.nEndPos); V|A.M-XLv4
} De3;}]wC
output.close(); 4 dHGU^#WZ
} Vel(+HS
catch(IOException e){e.printStackTrace ();} 1\Bh-tzB
catch(Exception e){e.printStackTrace ();} )+v5H
} xK0;saG#
Q(x=;wf5r
wY8Vc"
//读取保存的下载信息（文件指针位置） >=rniHs=?7
private void read_nPos() 5O~xj:
{ JoB-&r}\V*
try{ (=rDt93J
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !p ~.Y+
int nCount = input.readInt(); A"DGn
nStartPos = new long[nCount]; Te!eM{_$T
nEndPos = new long[nCount]; K\RMX?YsP
for(int i=0;i<nStartPos.length;i++) ~6u|@pnI
{ O d6'bO;G
nStartPos = input.readLong(); (0_]=r=q
nEndPos = input.readLong(); @VND}{j
} !#5y%Bf
input.close(); S"+#=C
} Pr1OQbg]8
catch(IOException e){e.printStackTrace ();} M_?B*QZJI
catch(Exception e){e.printStackTrace ();} KKg\n^
} ndBqXS
HA$7Q~{N-t
D!)h92CIDm
private void processErrorCode(int nErrorCode) IAmMO[9H
{ bLggh]Fh
System.err.println("Error Code : " + nErrorCode); RXWdqaENx
} +5GC?cW
-G1R><8[
:-2sKD y
//停止文件下载 L]X Lv9J0
public void siteStop() ]G! APE
{ H]dN'c-
bStop = true; B(wi+;
for(int i=0;i<nStartPos.length;i++) m KKa0"
fileSplitterFetch.splitterStop(); #)T'a
dDYor-g>
v49i.c9
} Ox aS<vQ3
} aXbj pb+
//负责部分文件的抓取 cnDBT3$~Z
**FileSplitterFetch.java 5tVg++I
*/ P6'0:M@5
package NetFox; `Z`o[]%
Nc(A5*
{X\FS
import java.io.*; >ZAn2s
import java.net.*; Pi[(xD8
DY87NS*HF
rN~V^k
public class FileSplitterFetch extends Thread { U<yKC8
pAtxEaXh
f*[Uq0?
String sURL; //File URL Kku@!lv
long nStartPos; //File Snippet Start Position Nu; 9
long nEndPos; //File Snippet End Position zL+M-2hV
int nThreadID; //Thread's ID |P"kJ45
boolean bDownOver = false; //Downing is over rIj B{X{Z
boolean bStop = false; //Stop identical j+3=&PkA.]
FileAccessI fileAccessI = null; //File Access interface C:}"?tri
p#dYNed]'
{<Vw55)#0Q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'p,54<e
{ `[4{]jX+<
this.sURL = sURL; rdm&YM`J
this.nStartPos = nStart; Kx,<-]4
this.nEndPos = nEnd; 0~nub
nThreadID = id; ){i 9,u")
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K~\Ocl
} Y{dj~}mM+
/.@"wAw:
?7aeY5p
public void run() v1s0kdR,>
{ h\OMWJ~
while(nStartPos < nEndPos && !bStop) 09HqiROw
{ ?xCWg.#l4V
jL#`CD
<SNu`,/I
try{ &B ^LaRg
URL url = new URL(sURL); :.fm LL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fUS1`
httpConnection.setRequestProperty("User-Agent","NetFox"); H_7EK
String sProperty = "bytes="+nStartPos+"-"; e:RgCDWL
httpConnection.setRequestProperty("RANGE",sProperty); e[L%M:e9U
Utility.log(sProperty); V3>JZH`
A#Jx6T`a
(K|7T{B
InputStream input = httpConnection.getInputStream(); ]9NA3U7F
//logResponseHead(httpConnection); GUqBnRA8j
O/PO?>@-/
CR'1,
byte[] b = new byte[1024]; OOj}CZ6
int nRead; 4xD`Z_U
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B)u*c]<qU
{ -1tiy.^$F
nStartPos += fileAccessI.write(b,0,nRead); ps3jw*QZ{5
//if(nThreadID == 1) p;9"0rj,z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); JWvL
} [$%O-_x
FWDAG$K@0
K)F6TvWv
Utility.log("Thread " + nThreadID + " is over!"); (E]q>'X
bDownOver = true; |'N)HH>;
//nPos = fileAccessI.write (b,0,nRead); *'hJ5{U
} R&]#@PW^
catch(Exception e){e.printStackTrace ();} w>h\643
} g.T:72"
} I7e.pm
6$A>%Jtwe
0 pPSg9
//打印回应的头信息 $ucA.9pJ
public void logResponseHead(HttpURLConnection con) %,Lv},%Y
{ ~l"]J'jF"H
for(int i=1;;i++) <3C/t|s
{ |!E: [UH
String header=con.getHeaderFieldKey(i); ?n(OH~@$i
if(header!=null) yU'<b.]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); XsbYWJdds
Utility.log(header+" : "+con.getHeaderField(header)); :.aMhyh#*
else Tqj:C8K{
break; z^^)n
} U;#9^<^
} omzG/)M:O
x ?24oO
&hu>yH>j
public void splitterStop() " `FcW
{ TP{2q51yM
bStop = true; #Ic)]0L
} o&ETs)n|
M`)/^S9
aI;-NnC
} dJ>~
qV79bK
g+A>Bl3#
/* B;e (5y-
**FileAccess.java <NWq03:&
*//文件访问(定位，写) 2"6bz^>}
package NetFox; gy>B 5ie
import java.io.*; Q>(a JF
s>*xAIx
4i7+'F
public class FileAccessI implements Serializable{ 5Mz:$5Tm
ny1;]_X_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _;M3=MTM9
RandomAccessFile oSavedFile; vb6kr?-i*
long nPos; h8dFW"cpC
LwYWgT\e
1Li*n6tLX`
public FileAccessI() throws IOException F3[,6%4v
{ BU#3fPl
this("",0); T@A Qe[U'v
} mv7W03
m!5Edo-;<
gxx#<=`
public FileAccessI(String sName,long nPos) throws IOException 1YK(oRSDn
{ J$5Vjh'aM
oSavedFile = new RandomAccessFile(sName,"rw"); .,20_<j%=
this.nPos = nPos; Ol~M BQs
oSavedFile.seek(nPos); #_{Q&QUk
} WdH/^QvTP
Z?xRSi2~7
vA}_x7}n(
public synchronized int write(byte[] b,int nStart,int nLen) mRa\ wEg%
{ T+^c=[W
int n = -1; 0(*L)s,5
try{ j+@3.^vK
oSavedFile.write(b,nStart,nLen); ]f0OmUHR5i
n = nLen; t1]/Bw`j/
} z:4_f:70
catch(IOException e) @$~IPg[J
{ <Se9aD
e.printStackTrace (); 'NZ=DSGIy
} 5VJe6i9;
Ulx]4;uzf
> K?OsvX
return n; +FAj30
} UKQ"sC
B0%=!&
=MMd&
} !1fZ7a
O`Gq7=X
@0 /qP<E
/* 5|nc^ 12
**SiteInfoBean.java oFf9KHorW
*/ g(WP
package NetFox; (v%24bv
@1Q-.54a
uINdeq7|F
public class SiteInfoBean { 7oWMjw\
~y2zl
!7 dct#4
private String sSiteURL; //Site's URL V@!)Pw
private String sFilePath; //Saved File's Path dniU{v
private String sFileName; //Saved File's Name }}{n|l+R5
private int nSplitter; //Count of Splited Downloading File kB> ~Tb0
pX ^^0
!6T"J!F#
public SiteInfoBean() 0n}13u=}
{//nSplitter的缺省值为5 <"J]u@|
//default value of nSplitter is 5 k(l2`I4V
this("","","",5); `daqzn
} WXl+w7jr
"(^XZAU#W
"|L"C+tE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y~-y\l;Tr
{ NEIkG>\7q
sSiteURL= sURL; ^ RA'E@"
sFilePath = sPath; }OL"38P
sFileName = sName; @#)` -]g
this.nSplitter = nSpiltter; S{rltT-
8w&-O~M
{`QHg O
} 'J|)4OG:
_1p8(n
l%0bF9\
public String getSSiteURL() rp||#v0l!w
{ /x6p
return sSiteURL; [y[d7V9_o
} ^dHQ<L3.*
z1PwupXt1
NXU:b"G S
public void setSSiteURL(String value) IOcQI:4.`
{ /o9T [^\
sSiteURL = value; qTd[DaG#
} W)In.?>]W
Cbw *?9d
r~t`H*C)}
public String getSFilePath() 1F^Q*t{
{ B`~EA] d
return sFilePath; Gk,Bx1y
} EKwQ$?I
M&Ka^h;N
K,E/.Qe\C
public void setSFilePath(String value) t'eqk#rq
{ 1-KNXGb'
sFilePath = value; 9DxHdpOk
} m1"m KM
/`*{57/3
:!`"GaTy
public String getSFileName() [XfR`@
{ -+#%]P8l
return sFileName; Gm=qn]c
} -Zt!H%U
N9e'jM>Oos
{VgE07r
public void setSFileName(String value) ')X(P>
{ $~/2!T_
sFileName = value; f-ltV<C_
} BQ@7^E[
6K/RO)
WJShN~ E
public int getNSplitter() "[bkdL<
{ CWj_K2=d
return nSplitter; N'Gq9A
} <Vat@e
`zd,^.i5~
)`u17 {
public void setNSplitter(int nCount) kB7vc>@1
{ H?$dnwR
nSplitter = nCount; B=_w9iVN
} U( YAI%O
} Y-VDi.]W
4>JSZ6i#n
48^-]};
/* }K{1Bm@S
**Utility.java _jWs(OmJ
*/ YagfCi ?
package NetFox; K9!HW&?<|
]33!obM
%xt9k9=vZ
public class Utility { LUOjaX
wi(Y=?=
Ln"wjO,
public Utility() YIQD9
{ xc^@"
agIqca;
p{f R$-d
} x/|W;8g4
q<3nAE$?=
//线程睡眠 !fh (k
public static void sleep(int nSecond) {)YbksrJ{
{ a:FU- ^B4~
try{ bI):-2&s}
Thread.sleep(nSecond); +m=b "g
} GQ2GcX(E(
catch(Exception e) umYsO.8
{ uD\R3cY
e.printStackTrace (); i7x&[b
} rQ*+ <`R}
} c%&,(NJ]K
"?" :
//日志 FP@_V-
public static void log(String sMsg) ,=/9Ld2w9
{ wNB?3v{n
System.err.println(sMsg); 'L/)9.29
} `<XS5h h=
Yuv(4a<M%
OC! {8MR
public static void log(int sMsg) (zhZ}C,VF
{ 2&6D`{"P
System.err.println(sMsg); WQ|Ufl;
} Fh~9(Y#
} 7nt(Rtbsu
mnt&!X4<
%bcf%7
/* pa-*&p
**TestMethod.java kZ9Gl!g
*/ 5ibr1zs
package NetFox; j.M]F/j
+17!v_4^
yg\QtWWM
public class TestMethod { =?]`Xo,v~
*|&Y ,H?
g[cnaS|?
public TestMethod() z~{08M7
{ ///xx/weblogic60b2_win.exe I:dUHN+@L5
try{ ^-%'ItVO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l;-2hZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); |Iy;_8c
SiteFileFetch fileFetch = new SiteFileFetch(bean); !(*&P
fileFetch.start(); "rdpA[>L
} enk`I$Xx
catch(Exception e){e.printStackTrace ();} W@"Rdc-
'a(y]QG
;CO qu#(
} VEV?$R7;
y[J9"k(@
^"Bhp:o2
public static void main(String[] args) " ILF!z
{ $uLTYu
new TestMethod(); <*vR_?!
} $H*8H`
} bAlty}U
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