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)); ]DZ~"+LaG
} 0 n|>/i
for(int i=0;i<nEndPos.length-1;i++) [9yy<Z5
{ 1=^|
nEndPos = nStartPos[i+1]; #5X+.!L
} b>'c
nEndPos[nEndPos.length-1] = nFileLength; hF1Lj=x
} ]v_u2f'
} `U>]*D68
-8SZ}J
>Hd!o"I
//启动子线程 hS^8/]E={
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NQN?CBFQ
for(int i=0;i<nStartPos.length;i++) zGP@!R`_
{ 9zpOp-K6
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f2ck=3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m-Se-aF
nStartPos,nEndPos,i); 6-\M }xq?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6dRvx;d
fileSplitterFetch.start(); OZe`>Q6
} 1.nYT*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R!>SN0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d\tA1&k71
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EEHTlqvR
nEndPos = " + nFileLength); 3+!G9T!
// fileSplitterFetch[nPos.length-1].start(); 0uI=8j
W QeQ`pM
x. /WP~I
//等待子线程结束 G6X5`eLQ
//int count = 0; BD M"";u
//是否结束while循环 F*y7 4j,
boolean breakWhile = false; ~Vc`AcWP
Z_Y gV:jc
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while(!bStop) qh6Q#s>tH
{ |gfG\fL3V
write_nPos(); |8akp
Utility.sleep(500); |
breakWhile = true; \CYKj_c
:7s2M
B06W(y,3Q>
for(int i=0;i<nStartPos.length;i++) cfHtUv
{ VzWH9%w
if(!fileSplitterFetch.bDownOver) '.7ER
{ 2UTmQOm
breakWhile = false; -LlS9[r0
break; k jx<;##R8
} :79u2wSh
} ]'0}fuV
if(breakWhile) ?p>m;Aq
break; "lB%"}
z#d*Odc
-s7a\H{~
//count++; zTw<9Nf
//if(count>4) .Z@iz5
// siteStop(); Q|7m9~
} )p{,5"0u
&HqBlRo
|zy` ]p9
System.err.println("文件下载结束！"); z:A_
} caL\ d
catch(Exception e){e.printStackTrace ();} $]J<^{v
} wKbU}29c
8,)<,g-/=
0*KL*Gn
//获得文件长度 )vGxF}I3
public long getFileSize() O*>`md?MH
{ +[[^W;<.l
int nFileLength = -1; R'^J#"[
try{ eo&G@zwN
URL url = new URL(siteInfoBean.getSSiteURL()); zuJ@@\75
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m=60a@o]
httpConnection.setRequestProperty("User-Agent","NetFox"); H2yPVJ\Y)"
4UMOC_
r(g#3i4Q
int responseCode=httpConnection.getResponseCode(); N^'(`"J s
if(responseCode>=400) jN/snU2\0
{ jT4 m(j
processErrorCode(responseCode); pwA~?$B1
return -2; //-2 represent access is error =TA8]7S~U
} 7LiyA<
bj@f<f`
/wi/i*;A
String sHeader; )eH?3""
#`%V/#YK
FW3uq^
for(int i=1;;i++) D=M'g}l
{ mJsU7bD`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 12l1u[TlS
//Utility.log(in.readLine()); |)[&V3+|
sHeader=httpConnection.getHeaderFieldKey(i); R?#.z#
if(sHeader!=null) UTO$L|K
{ KBgFS%-W
if(sHeader.equals("Content-Length")) 2|${2u`$&y
{ -+:t%A?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VwT&A9&{8
break; .RWq!Z=)3
} _D8:p>=
} _TbvQY
else RG_6& A
break; }5}#QHF
} WdbHT|.Aj
} [f]:hJi
catch(IOException e){e.printStackTrace ();} !j9(%,PR
catch(Exception e){e.printStackTrace ();} J$S*QCo
Qa"4^s
/mK]O7O7
Utility.log(nFileLength); A$l
}&^1")2t
pbGv\SF
return nFileLength; tQ)l4Y 8
} ;7(vqm<V2~
A"IaFXB
vg5fMH9ZZ
//保存下载信息（文件指针位置） e4;h*IQK
private void write_nPos() ;ao <{i?
{ 03!#99
try{ -9R.mG
output = new DataOutputStream(new FileOutputStream(tmpFile)); m(CsO|pz
output.writeInt(nStartPos.length); (w Q,($@
for(int i=0;i<nStartPos.length;i++) ^j2z\yo
{ H:mcex
// output.writeLong(nPos); u|(Iu}sE=
output.writeLong(fileSplitterFetch.nStartPos); b\H,+|iK
output.writeLong(fileSplitterFetch.nEndPos); 9jllW[`2F
} \\Nt^j3qR
output.close(); 0RN7hpf&`
} J5}?<Dd:
catch(IOException e){e.printStackTrace ();} Z*.rv t
catch(Exception e){e.printStackTrace ();} Q>TNzh
} jV#1d8qm
WPPDvB
G9CL}=lJ,
//读取保存的下载信息（文件指针位置） J!yK/*sO,
private void read_nPos() M[L@ej
{ 8]WcW/1r !
try{ s 4n<k]d
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); i1!Y{
int nCount = input.readInt(); &0OH:P%
nStartPos = new long[nCount]; B.#-@
nEndPos = new long[nCount]; |oR#j `
for(int i=0;i<nStartPos.length;i++) vhN6_XD
{ .GvZv>
nStartPos = input.readLong(); {T3wOi
nEndPos = input.readLong(); X @X`,/{X
} iN2591S
input.close(); ucUuhS5
} LftzW{>gI"
catch(IOException e){e.printStackTrace ();} jK2gc^"t
catch(Exception e){e.printStackTrace ();} y 48zsm{
} /Ur]U w
Rj-4K@a8#N
#/)U0IR)
private void processErrorCode(int nErrorCode) r<'B\.#tp>
{ %< Jj[F
System.err.println("Error Code : " + nErrorCode); %/R[cj8
} /.(F\2+A
FmQiy+.|
7+rroCr"
//停止文件下载 $^W|@et{ ]
public void siteStop() >skl-f
{ t!0 IQ9\[*
bStop = true; cd4HbSp
for(int i=0;i<nStartPos.length;i++) )~#3A@
fileSplitterFetch.splitterStop(); 6`5DR~
$"3cN&
xC2y/?
} _w7yfZLv+
} h-\+# .YP
//负责部分文件的抓取 *?o 'sTH
**FileSplitterFetch.java ?*cCn-|
*/ `r0MQkk
package NetFox; T!>sL=uf
r`PD}6\
+SkfT4*U
import java.io.*; ePTxuCf>
import java.net.*; >vNE3S_
$Eo-58<q
s2 $w>L
public class FileSplitterFetch extends Thread { 2=X.$&a
t5EYu*
J n'SGR
String sURL; //File URL u`u{\ xN9
long nStartPos; //File Snippet Start Position ^h"@OEga?
long nEndPos; //File Snippet End Position c`7dNx
int nThreadID; //Thread's ID PsN_c[+
boolean bDownOver = false; //Downing is over VRUA<x
boolean bStop = false; //Stop identical 3u9}z+q
FileAccessI fileAccessI = null; //File Access interface l)Mi?B~N
Oo9'
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Om2w+yU
{ 66scBi_d
this.sURL = sURL; ~FnY'F<35
this.nStartPos = nStart; ;V84Dy#b
this.nEndPos = nEnd; e,l-}=5*P
nThreadID = id; i_p-|I:hQ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 a!,X@5
} n{"a0O
:71St'
[f=Y*=u9,
public void run() 1/c+ug!y
{ %ejq|i7
while(nStartPos < nEndPos && !bStop) K/8TwB?I
{ 4 Z&KR<2Z
seZb;0
^_uCSA'X
try{ eqqnR.0
URL url = new URL(sURL); ME*A6/h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S4 s#EDs
httpConnection.setRequestProperty("User-Agent","NetFox"); </_.+c [
String sProperty = "bytes="+nStartPos+"-"; 0Q[;{}W}
httpConnection.setRequestProperty("RANGE",sProperty); }`]Et99Q5
Utility.log(sProperty); lDZ~
l_zTpyOZ
BVS SO's
InputStream input = httpConnection.getInputStream(); >txeo17Ba\
//logResponseHead(httpConnection); 5e&;f
%.;;itB
^t,haO4
byte[] b = new byte[1024]; V2$M`|E
int nRead; '|G8yojz
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [x -<O:r=P
{ {N@Pk[!
nStartPos += fileAccessI.write(b,0,nRead); G}@a]EGm
//if(nThreadID == 1) Xi!e=5&Pa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~Sx\>wBlc
} 6ck%M#v
6u{%jSA>D\
]6,D9^{;
Utility.log("Thread " + nThreadID + " is over!"); 3]kN9n{
bDownOver = true; >C`#4e?}
//nPos = fileAccessI.write (b,0,nRead); bl#6B.*=
} %Hu.FS5'
catch(Exception e){e.printStackTrace ();} #j"GS/y"
} 5i%\m
} .d+zF,02Z
xxOhGA)
V9wL3*
//打印回应的头信息 ,Uy;jk
public void logResponseHead(HttpURLConnection con) 'Qg.D88
{ &5QvUn
for(int i=1;;i++) x|g2H.n
{ 8[:G/8VI
String header=con.getHeaderFieldKey(i); Nop61zj
if(header!=null) "_:6v64Gx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yh.WTgcW
Utility.log(header+" : "+con.getHeaderField(header)); 'a>D+A:
else -0<ZN(?|
break; )*aAkM
} BqtN=
} p:3w8#)MZ
wcGv#J],
n/YnISt
public void splitterStop() ulfs Z:
{ lLI%J>b@
bStop = true; *pyC<4W
} ?5wsgP^
JX`>N(K4\
BJ{?S{"6%G
} oslj<
QRwOv
im F,8'
/* 6rlvSdB
**FileAccess.java ]hZk#rp}
*//文件访问(定位，写) GK#D R/OM
package NetFox; D[{"]=-
import java.io.*; VREDVLQT
olK*uD'`
<eZrb6a'
public class FileAccessI implements Serializable{ Z 4c^6v
upFe{M@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \jAI~|3
RandomAccessFile oSavedFile; ,C|aiSh0-
long nPos; )))AxgM
?',Wn3A
\\35} 9
public FileAccessI() throws IOException XnRm9%
{ ^MVOaV65
this("",0); o5G]|JM_
} P=X)Ktmv
OXZx!h
ScRK1
public FileAccessI(String sName,long nPos) throws IOException OK2\2&G
{ hPUZ{#;n
oSavedFile = new RandomAccessFile(sName,"rw"); ?"@SxM~\
this.nPos = nPos; {ea*dX872:
oSavedFile.seek(nPos); R S] N%`]
} kD6Iz$tr
4v2JrC;
5Hs!s+
public synchronized int write(byte[] b,int nStart,int nLen) 1;vwreJ
{ }xY|z"&
int n = -1; rw75(Lp{
try{ |C>\ku*
oSavedFile.write(b,nStart,nLen); -o57"r^x
n = nLen; 1U ='"
} EW/NH&{
catch(IOException e) 'lmjZ{k
{ \!k\%j9
e.printStackTrace (); A@reIt
} ?28)l 4 Ml
In*0.
{fMo#`9=
return n; Z1wfy\9c8
} :)Da^V
Me^L%%:@
=q[ynZ8O\w
} 1"T&B0G3l
B0^:nYko
rK4 pYo
/* ?S.LGc
**SiteInfoBean.java ~xc0Ky?8
*/ S}K-\[i?
package NetFox; 'Y/8gD~.
.[Ny(X/]/}
>Fc=F#tA9
public class SiteInfoBean { &+/$~@OK
Zm#,Ike?#
'@"A{mrE
private String sSiteURL; //Site's URL <XzRRCYQ
private String sFilePath; //Saved File's Path ='(;!3ZH
private String sFileName; //Saved File's Name EpENhC0
private int nSplitter; //Count of Splited Downloading File vb`:
Qd}h:U^
'(8} <(%
public SiteInfoBean() ryTtGx%a
{//nSplitter的缺省值为5 l{V(Y$xp3
//default value of nSplitter is 5 V_KHVul
this("","","",5); X$ A ]7t
} =HMuAUa.
YW"nPZNPy~
nDNK}O~'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 'f6!a5qC
{ O\w-hk
sSiteURL= sURL; bLUyZ3m!
sFilePath = sPath; <O{G&
sFileName = sName; 6lwWFR+k
this.nSplitter = nSpiltter; VGOdJ|2]Wr
UO-,A j*wW
%gTY7LIe1z
} I!.-}]k
7QaZ|\c
A$TFa:O|
public String getSSiteURL() Q|Nw @7$`
{ p(A[ah_
return sSiteURL; 8vUq8[[
} "p&4Sn3T2?
Dj w#{WR
W;8}`k
public void setSSiteURL(String value) 2F:X:f
{ z{qn|#}
sSiteURL = value; Bc}e ??F
} M2nZ,I=l
'A/f>W
x^ sTGd
public String getSFilePath() lsVg'k/Z!
{ ~%sNPKjA
return sFilePath; ] .c$(.
} qwo{34
W}k)5<C4v
1["IT.,f.
public void setSFilePath(String value) 'he&h4fm
{ >P2QL>P
sFilePath = value; &tw{d DD6
} dVBr-+
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"-G&]YMl
public String getSFileName() Tg v]30F)
{ wA6<BujD
return sFileName; weIlWxy
} )lVplAhZD
smX&B,&@
7] 17?s]t,
public void setSFileName(String value) WQHlf0]
{ m_UzmWF
sFileName = value; &-|(q!jm
} a6g+"EcH#'
(M%ZSF V
+VHoYEW
public int getNSplitter() `~LaiN.
{ }k6gO0z
return nSplitter; 1VG7[#Zy
} 3L;&MG=
_\AT_Zmy
</qli-fXB}
public void setNSplitter(int nCount) J8hH#7WMS
{ -[7S.
nSplitter = nCount; {^Q1b.=
} >8DZj&j
} AHTQF#U^
0EUC8Ni
'>UQsAvm
/* 9K#U<Q0b'
**Utility.java )7iYx{n
*/ @.KFWAm
package NetFox; fMZc_dsW9
g=kuM
}_cX" s
public class Utility { .T7S1C $HP
wTVd){q`.
-[>G@m:?e
public Utility() {IQCA-AI
{ WSV% Oy3V
~`VD}{[,B
vce1'aW
} 3HB(rTw
Ndqhc
//线程睡眠 %;YERO!
public static void sleep(int nSecond) :JG2xtn
{ |dk9/xdX
try{ mV'^4by
Thread.sleep(nSecond); RhumNP<M
} {b26DKkQS
catch(Exception e) tfq; KR
{ )R"deb=s
e.printStackTrace (); OEj%cB!
} *qL"&h5W
} u[1'Ap
T~-PT39E
//日志 OwG:+T_
public static void log(String sMsg) |%7OI#t^
{ G:?l;+P1
System.err.println(sMsg); "(SZ;y
} -$5nqaK?
3']=w@~ O[
Lw #vHNf6
public static void log(int sMsg) aG/L'weR
{ aT%6d@g
System.err.println(sMsg); bY7~b/
} ^1w*$5YI
} @P}!mdH1
s4Y7x.-
'5m`[S-IU
/* 'Lv>!s 7
**TestMethod.java "r.eN_d
*/ ao.v]6a
package NetFox; p+d?k"WN?
k6W [//
ys$X!Ep
public class TestMethod { <bxp/#6D
+UC-
*[[TDduh&
public TestMethod() <)$b=z
{ ///xx/weblogic60b2_win.exe 7"Iagrgw
try{ U4$CkTe2Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); t(?tPt4zp
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9<S};I;
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,mW-O!$3W
fileFetch.start(); Zp*0%x!e
} F B7.b
catch(Exception e){e.printStackTrace ();} 7Yd]#K{$
{pW(@4U
M4(`o^n
} # ~T KC|G
k->cqtG
4mJ[Wr\y
public static void main(String[] args) p(]o#$ 6[
{ aw8q}:
new TestMethod(); ia}V8i
} |qTS{qQh{L
} 8q#Be1u<s2
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