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)); 2Z%n "z68
} -gm5Eqi
for(int i=0;i<nEndPos.length-1;i++) -fXQ62:S
{ xT]t3'y|-
nEndPos = nStartPos[i+1]; yo/;@}g}
} /]^Y\U^
nEndPos[nEndPos.length-1] = nFileLength; ^C1LQZ
} ge(,>xB
} 8lzoiA_9
`g3AM%3
!Ve0:$
//启动子线程 LRts W(A/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qB (Pqv
for(int i=0;i<nStartPos.length;i++) #>("(euXMF
{ LWm1j:0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bm 4RRI
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y!_{:2H8p
nStartPos,nEndPos,i); IdN3Ea]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); / Ws>;0
fileSplitterFetch.start(); 0&j90J$`
} 7P<f(@0h$E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /'aqQ K<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (Hj[9[=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;Mo_B9
nEndPos = " + nFileLength); ge1. HG
// fileSplitterFetch[nPos.length-1].start(); \*=wm$p&*
9?MzIt
J@2wPKh?Yp
//等待子线程结束 "3\y~<8%'
//int count = 0; ||>4XDV#
//是否结束while循环 hNsi 8/
boolean breakWhile = false; w2UEU5%
*U,JQ
`_)H aF>/
while(!bStop) vQyY %
{ Vx2/^MiXy
write_nPos(); JPAjOcmU/
Utility.sleep(500); g i6s+2
breakWhile = true; fs 2MYat
l=p_
5{k,/Z[L
for(int i=0;i<nStartPos.length;i++) 'E9{qPLk(
{ x<M::")5!V
if(!fileSplitterFetch.bDownOver) wpuK?fP
{ 6ICW>#fI`
breakWhile = false; \OtreYi
break; 'mbLK#q
} o+&Om~W
} JR#4{P@A
if(breakWhile) ,wes*
break; #55:qc>m
<O 0Q]`i
V%s7*`U
//count++; (87| :{
//if(count>4) ~Ym_ {
// siteStop(); $uDgBZA\
} p$9Aadi]
/ Qd` ?
6vsA8u(|V#
System.err.println("文件下载结束！"); eZAMV/]jH
} A~PR
catch(Exception e){e.printStackTrace ();} TT/H"Ri}Jp
} tngB;9c+w
QF/_?Tm4
zP%s]>hH
//获得文件长度 Z8ea)_{#
public long getFileSize() \hgd&H0UU
{ P0}{xq'k9v
int nFileLength = -1; 9>w~B|/
try{ 3\@2!:>
URL url = new URL(siteInfoBean.getSSiteURL()); &Y?t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); olv?$]
httpConnection.setRequestProperty("User-Agent","NetFox"); iW(LD1~7
`!Z?F]):G
HvG %##
int responseCode=httpConnection.getResponseCode(); u_$4xNmQ
if(responseCode>=400) dEtjcId
{ ;6P>S4`w
processErrorCode(responseCode); hg" i;I
return -2; //-2 represent access is error ]"Uzn
} (T#$0RFq
qisvGHo
Q}@t'
String sHeader; xyL)'C
B#S8j18M
0fXMY-$I
for(int i=1;;i++) NUYKMo1ze
{ G-T^1?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); * )<+u~
//Utility.log(in.readLine()); 8F8?1
sHeader=httpConnection.getHeaderFieldKey(i); S[3"?$3S
if(sHeader!=null) ,~naKd.ZY
{ e9{0hw7
if(sHeader.equals("Content-Length")) dgpE3 37Lt
{ !2KQi=Ng
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); PiKP.
break; o@zxzZWg
} 6]b"n'G
} aNEah
else uKP4ur@1
break; FSA%,b;U
} \uOM,98xS
} uVn"L:_
catch(IOException e){e.printStackTrace ();} Ahwi
catch(Exception e){e.printStackTrace ();} RH;ulAD6(~
\s&Mz;:
nUP, Yd
Utility.log(nFileLength); d=xjLbsZ
^7spXfSAd
a{T.U-0
return nFileLength; 7x6M]1F
} adP :{j
(0NffM1
mp8GHV
//保存下载信息（文件指针位置） "5V;~}=S
private void write_nPos() 60!%^O =
{ jG[Vp b
try{ 6/8K2_UeoW
output = new DataOutputStream(new FileOutputStream(tmpFile)); \~hrS/$[$
output.writeInt(nStartPos.length); PK2;Ywk`
for(int i=0;i<nStartPos.length;i++) 6h>#;M
{ 5U~KYy^v
// output.writeLong(nPos); hi[nUG(OI
output.writeLong(fileSplitterFetch.nStartPos); %, psUOY
output.writeLong(fileSplitterFetch.nEndPos); +-@n}xb@
} =Pl@+RgK+
output.close(); 2nkA%^tR
} FYYc+6n
catch(IOException e){e.printStackTrace ();} T%eBgseS
catch(Exception e){e.printStackTrace ();} JI-i7P
} cpjwc@UMe
H:c5 q0O^x
9i5?J]o^
//读取保存的下载信息（文件指针位置） UUV5uDe>i
private void read_nPos() F<I*?${[
{ ;98&5X\u<
try{ [nO3%7t@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $K^l=X
int nCount = input.readInt(); #h[>RtP:
nStartPos = new long[nCount]; (I}owr5:
nEndPos = new long[nCount]; OZxJDg
for(int i=0;i<nStartPos.length;i++) * hs&^G
{ 0A)0Zw
nStartPos = input.readLong(); ,>-D xS
nEndPos = input.readLong(); oFU:]+.+D
} TWpw/osW
input.close(); = J;I5:J
} x 7by|G(
catch(IOException e){e.printStackTrace ();} z{L'7
catch(Exception e){e.printStackTrace ();} MV"n{1B
} d%8n
d-~V.
srv4kodj
private void processErrorCode(int nErrorCode) 44ty,M3
{ _X4Y1zh
System.err.println("Error Code : " + nErrorCode); S $p>sItO
} 1jg* DQ7L
4,sE{%vb
fY00
//停止文件下载 wb.yGfJ
public void siteStop() _aFe9+y
{ Mr)t>4
bStop = true; h=A
for(int i=0;i<nStartPos.length;i++) "bhK%N;
fileSplitterFetch.splitterStop(); Nnh\FaI
[K3 te
|c/=9Bb
} z{W Cw
} u4Nh_x8\Nr
//负责部分文件的抓取 @Y/&qpo$#W
**FileSplitterFetch.java UT\4Xk<
*/ /yG7!k]Eg
package NetFox; OeqKKVuQ
inGUN??
.}\8Y=
import java.io.*; f`hZb
import java.net.*; =VD],R)
>_2~uF@pb
;TJpD0
public class FileSplitterFetch extends Thread { n*7^lAa2
O{l4 f:51
zTa5N
String sURL; //File URL x:FZEyalG
long nStartPos; //File Snippet Start Position /"Vd( K2Z
long nEndPos; //File Snippet End Position XjN4EDi+E
int nThreadID; //Thread's ID B"_O!
boolean bDownOver = false; //Downing is over 2GptK"MrD
boolean bStop = false; //Stop identical v?VDASR2`
FileAccessI fileAccessI = null; //File Access interface >Q/;0>V
V$ H(a`!
h <4`|Bg+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /i,n75/y?
{ Lu}jk W*
this.sURL = sURL; "QnYT3[l"
this.nStartPos = nStart; c~vhkRA
this.nEndPos = nEnd; \n[kzi7
nThreadID = id; VCWW(Y1Fd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I<#X#_YP
} $+Ze"E
G3DgB!
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public void run() +aOdaNcI
{ I}_}VSG(
while(nStartPos < nEndPos && !bStop) BY~Tc5
{ {mJ' Lb0;
r:bJU1P1$s
2=_$&oT**
try{ EHC7b^|3}
URL url = new URL(sURL); ~X3g_<b_8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F}}!e.>c
httpConnection.setRequestProperty("User-Agent","NetFox"); #yH+ENp0
String sProperty = "bytes="+nStartPos+"-"; 2Xe1qzvo
httpConnection.setRequestProperty("RANGE",sProperty); BH0m[9nU;
Utility.log(sProperty); 76tn`4NIP
eUy*0
&[[r|
InputStream input = httpConnection.getInputStream(); Nm"P8/-09
//logResponseHead(httpConnection); NBPP?\1
!i"zM}
$9`#p/V
byte[] b = new byte[1024]; c& ;@i$X(
int nRead; ..JRtuM-v
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U823q-x
{ M8~3 0L
nStartPos += fileAccessI.write(b,0,nRead); #s{^fUN6
//if(nThreadID == 1) '{ _ X1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \\R}3 >Wc
} E]' f&0s
(u&x.J
Or? )Nlg6x
Utility.log("Thread " + nThreadID + " is over!"); I!L J&>
bDownOver = true; "J"=<_?
//nPos = fileAccessI.write (b,0,nRead); (m R)o&Y%,
} -$:;en?
catch(Exception e){e.printStackTrace ();} (,h2qP-;ud
} w1tM !4r
} zP44 Xhz
e{E\YEc
:(A&8<}-6
//打印回应的头信息 &G"s!:
public void logResponseHead(HttpURLConnection con) /0/ouA>+
{ PZ|I3z
for(int i=1;;i++) =Ydrct
{ >=0]7k;
String header=con.getHeaderFieldKey(i); T_D3WHp
if(header!=null) gxl7jY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $E@n;0P
Utility.log(header+" : "+con.getHeaderField(header)); &x1A{j_
else c-k3<|H`
break; P*6m~`"5
} M 2hZ'
} un 5r9
A`uHZCwJ5
iE''>Z
public void splitterStop() T_S3_-|{==
{ v*!N}1+J
bStop = true; K) }1;
} WAxNQfEe
(vG*)a
46g0 e
} 'JOCL0FP
gO8d2?Oh
-yf8
/* _ dAyw
**FileAccess.java $BdwKk !k
*//文件访问(定位，写) uA#K59E+
package NetFox; _z#"BN
import java.io.*; ~3.*b%,
qKD
4G,FJjE`p
public class FileAccessI implements Serializable{ 2 q4p-
9K@I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &\9%;k
RandomAccessFile oSavedFile; f- XUto
long nPos; &<;T$Y
vqN/crJ@
DP@1to@
public FileAccessI() throws IOException /Z6lnm7wJ
{ B/;>v
this("",0); *V kaFQZ$,
} M*0^<e~]F
q? ">
bh@CtnO
public FileAccessI(String sName,long nPos) throws IOException &{? M} 2I
{ +g g_C'"
oSavedFile = new RandomAccessFile(sName,"rw"); !CU-5bpu
this.nPos = nPos; %4LoEm=U
oSavedFile.seek(nPos); KyNu8s k
} K[icVT2v~
+ Tp% *
)Dz]Pv]H'
public synchronized int write(byte[] b,int nStart,int nLen) ym|7i9
{ L?/AKg
int n = -1; S=,czs3N
try{ l6bY!I>
oSavedFile.write(b,nStart,nLen); EsKgS\`RZ
n = nLen; hV(^Y)f
} Z;G*wM"
catch(IOException e) F- -g?Q^
{ D>y5&`
e.printStackTrace (); &)OI!^ (
} Zye04&x9k
"Ol:ni1
zwV!6xG
return n; \ UrD%;sq
} 08xo_Oysq
?XY'<]o E
KdkL_GSLT
} U3N d\b'0
7<)H?;~;
y7>3hfn~w
/* S'!&,Dxq^
**SiteInfoBean.java \(pwHNSafk
*/ > '=QBW
package NetFox; ];k!*lR)
)zxb]Pg+
L(yUS)O
public class SiteInfoBean { 2VY7?1Ab(@
:4zu.
le \f:
private String sSiteURL; //Site's URL /''=V.-N
private String sFilePath; //Saved File's Path f!kZyD7
private String sFileName; //Saved File's Name )l`Ks
private int nSplitter; //Count of Splited Downloading File +A?P4}
Bug.>ln1
q7lC}'2fu
public SiteInfoBean() _G'ki.[S7
{//nSplitter的缺省值为5 82@^vX
//default value of nSplitter is 5 ?7Cm+J
this("","","",5); >>T7;[h
} p(pfJ^/:(
PV#h_X<l%
B6dU6"
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !-`L1D_hy
{ %w^*7Oi
sSiteURL= sURL; A{s-g>s
sFilePath = sPath; zH~P-MqC
sFileName = sName; MJiVFfYW
this.nSplitter = nSpiltter; ntH`\ )xi
F2 B(PGa7
h|]cZMGo
} +\Vw:~e
~+1mH
KfjWZ4{v
public String getSSiteURL() _+48(QF<
{ ;J|t-$Z
return sSiteURL; Az@@+?,%Y
} X[$h &]
he~8V.$
$\ZWQct
public void setSSiteURL(String value) fJ8>nOh
{ Q`*U U82!
sSiteURL = value; <5G(Y#s/?
} )f$4:Pq
`F/R:!v
E "=4(
public String getSFilePath() +#,J`fV%
{ Z5TA4Q+Q
return sFilePath; Rf0so
} we_CF*zj
]AA|BeL?|
d2eXN3"
public void setSFilePath(String value) XB!qPh.
{ L'Cd`.yVO
sFilePath = value; A4,%l\di<
} BlpyE[h T
JE}VRMNr
5,,'hAq_
public String getSFileName() !@lx|=#
{ a!bW^?PcK
return sFileName; U Y*`R
} L91vp'+2
f#&z m} t
}6^5mhsL
public void setSFileName(String value) L E\rc A
{ Tl yyJ{~
sFileName = value; ?<jWEz=
} [q%`q`EG
60|PVsmDm
.<?7c!ho
public int getNSplitter() ;@S'8
{ |9XoRGgXU
return nSplitter; v_Vw!u
} e'uC:O.u
)w4U]inJ$"
MUbKlX
public void setNSplitter(int nCount) zlP{1z;nV
{ _LZ(HTX~
nSplitter = nCount; gd * b0(
} lZRO"[<
} 3U^Vz9LW
j~Pwt9G
[<,7LG<
/* v76P?[
**Utility.java gw"SKp!]
*/ w-JWMgY8w
package NetFox; [5'HlHK
Ba?1q%eG
! $mY.uu
public class Utility { +w[ZMk
#C }+
I)yaR+l
public Utility() }O+xs3Uv
{ iPl,KjGk
<xSh13<
&-FG}|*4M
} :ILpf+`yY
%Qz<Lk">.
//线程睡眠 MOh&1]2j5
public static void sleep(int nSecond) Pqx?0f)
{ 3r#['UmT
try{ W*s=No3C
Thread.sleep(nSecond); P !f{U;B
} \mLEwNhRY
catch(Exception e) `W}pAmhj
{ ?ch?q~e)
e.printStackTrace (); oU,8?(}'~
} 9O&m7]3
} z*.G0DFw
423%K$710
//日志 cvy 5|;-u
public static void log(String sMsg) ]#4kqj}
{ q !9;JrX
System.err.println(sMsg); 00D.Jn
} ;bG?R0a
jMBMqQNU
j5R0e}/r
public static void log(int sMsg) p,k1*|j
{ h1(i/{}:
System.err.println(sMsg); 1o/(fy
} OcMB)1uh\
} >"1EN5W
T^]]z}k
Q?T+^J
/* (KN",u6F
**TestMethod.java jNx{*2._r
*/ $k)K}U
package NetFox; kF'9@*?J
qbSI98rw
g$C]ln>"9m
public class TestMethod { 3pML+Y|ij
p=UW ^95
N`7OJ)l
public TestMethod() e;~(7/1
{ ///xx/weblogic60b2_win.exe c.1gQy$}|
try{ JE{cZ<NNH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2hNl_P~z1u
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +JG05h%'
SiteFileFetch fileFetch = new SiteFileFetch(bean); k@%5P-e}
fileFetch.start(); >{(c\oMD
} k(tB+k!vH\
catch(Exception e){e.printStackTrace ();} !21G$[H
UVLS?1ra
CLZj=J2
} >0:3CpO*
O[$X36z
n~ $S
public static void main(String[] args) aC=2v7*
{ 0sSBwG
new TestMethod(); NUb$PT
} bA0H
} ORKJy)*"
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