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)); %D%e:se
} 1\"BvFE*E~
for(int i=0;i<nEndPos.length-1;i++) P}w^9=;S
{ d!a2[2Us
nEndPos = nStartPos[i+1]; ]~4}(\u
} A5(kOtgiT
nEndPos[nEndPos.length-1] = nFileLength; ?j},O=JFn
} ?STI8AdO
} <"j"h=tm}
^MF=,U'8
&q"uy:Rd
//启动子线程 [qc6Q:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2/a04qA#
for(int i=0;i<nStartPos.length;i++) z.Ve#~\
{ ;NvhL|R
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :6HiP&<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =}6Z{}(TT
nStartPos,nEndPos,i); kiBOyC!r6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (RI>aDGRH
fileSplitterFetch.start(); Mz%d_
} qrORP3D@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w|3fioLs
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7ZR0M&pX
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bN<O<x1j
nEndPos = " + nFileLength); n^I|}u\
// fileSplitterFetch[nPos.length-1].start(); o9(#KC?3
E(L^hZMc
fitK2d
//等待子线程结束 QvyUd%e'5A
//int count = 0; g*\v}6 h
//是否结束while循环 dnhpWVhn
boolean breakWhile = false; QjT#GvHY
T!O3(
_s=Pk[e
while(!bStop) kB!M[[t
{ @b(gjOE
write_nPos(); LqH?3):
Utility.sleep(500); Qr xO erp
breakWhile = true; p%i .(A
>LRaIU>
p-ii($~}
for(int i=0;i<nStartPos.length;i++) 2{Lc^6i(t
{ qoyGs}/I8
if(!fileSplitterFetch.bDownOver) zv3<i (
{ kA->xjk
breakWhile = false; ;Ef)7GE@\[
break; ,YuWz$aF{
} FnU{C=P
} _{@}Fd?o
if(breakWhile) ^9m^#"ZW`
break; #v]aT ]}
l.LFlwt
YfYL?G
//count++; ~(L<uFU V
//if(count>4) -_H2FlB
// siteStop(); .<|4PG
} -2mOgv
$DMu~wwfG
3 %{'Uh,
System.err.println("文件下载结束！"); fn"jYSy
} ?&t|?@
catch(Exception e){e.printStackTrace ();} SGT-B.
} mfi'>o#
Zm'::+tl
c`[uQXv
//获得文件长度 pJ@DHj2@
public long getFileSize() &-.eu
{ 3t}o0Ai9
int nFileLength = -1; 1x5CsmS
try{ )6S}O* 1
URL url = new URL(siteInfoBean.getSSiteURL()); .J! $,O@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); YuZ
httpConnection.setRequestProperty("User-Agent","NetFox"); ROiX=i
"VOWV3Z
p!5JO4F$
int responseCode=httpConnection.getResponseCode(); _O71r}4
if(responseCode>=400) Hw-oh?=
{ IF21T
processErrorCode(responseCode); Yoym5<xE
return -2; //-2 represent access is error ?z36mj"`o
} XzwQ,+IAr
^)K[1]"uM
@9Pn(fd]
String sHeader; x@(f^P
%>}7$Y%
|gxB; GG
for(int i=1;;i++) 761"S@tf$}
{ 4BL,/(W] x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]3cf}Au
//Utility.log(in.readLine()); [~%;E[ky$
sHeader=httpConnection.getHeaderFieldKey(i); *j;r|P;g
if(sHeader!=null) * =N6_
{ oN}j<6s
if(sHeader.equals("Content-Length")) -2~yc2:>A
{ dD2e"OIX
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .j@n6RyN
break; Ljs(<Gm)-
} OehB"[;+
} ^bw~$*"j#
else H[yLlv
break; -m-WUox4"
} S6:gow(wU
} y#W8] <dS"
catch(IOException e){e.printStackTrace ();} G+yz8@
catch(Exception e){e.printStackTrace ();} `6F8Kqltr
AxQ/
{.)~4.LhQM
Utility.log(nFileLength); 8+b3u05
Sk%|-T(d$
~x\Q\Cxp
return nFileLength; &3/H P)*<]
} AR2+W^aM3
/{} ]Hu
l3$?eGGM
//保存下载信息（文件指针位置） 7oSuLo=
private void write_nPos() -$p-o Z)
{ <]`2H}*U'
try{ mTbPzZ4
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;]ew>P)
output.writeInt(nStartPos.length); )[Cm*Xxa$
for(int i=0;i<nStartPos.length;i++) bhT]zsBK
{ No+zw%l0E
// output.writeLong(nPos); PQay sdb
output.writeLong(fileSplitterFetch.nStartPos); ,4$J|^T&
output.writeLong(fileSplitterFetch.nEndPos); ~hX'FV
} =jHy6)6w
output.close(); "61n?Z#,M[
} #&gy@!a~
catch(IOException e){e.printStackTrace ();} 4<HJD&@V
catch(Exception e){e.printStackTrace ();} K6Ua~N^
} hY'%SV p
06O
/PS]AM
//读取保存的下载信息（文件指针位置） )Jn80~U|1
private void read_nPos() o%7yhCY
{ L0~O6*bk
try{ +?'acn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); YiMecu
int nCount = input.readInt(); `Nr7N#g+u
nStartPos = new long[nCount]; 14zzWzKx
nEndPos = new long[nCount]; l"#,O$x"#@
for(int i=0;i<nStartPos.length;i++) vnpX-c
{ 6dlPS{H#U
nStartPos = input.readLong(); D.f=!rT7E7
nEndPos = input.readLong(); zt6ep=
} ('oUcDOFTS
input.close(); &*SnDuc
} &GAx*.L
catch(IOException e){e.printStackTrace ();} E$ rSrT(
catch(Exception e){e.printStackTrace ();} fba3aId[
} N<%,3W_-_
R~([
a#=-Aj-
private void processErrorCode(int nErrorCode) 'z:p8"h}
{ &n wg$z{Y
System.err.println("Error Code : " + nErrorCode); ;C%EF
} yFqC-t-i
Ckp=d
/;1FZ<zU
//停止文件下载 $Tza<nA
public void siteStop() [x,&Gwa
{ /zKuVaC
bStop = true; 6iC:l%|u
for(int i=0;i<nStartPos.length;i++) !NtY4O/
fileSplitterFetch.splitterStop(); wr(?L7 $+
kzu=-@s
c#Bde-dh
} 5[k35c{
} $G[##j2
//负责部分文件的抓取 -M}iDBJx>#
**FileSplitterFetch.java mLO6`]p{H
*/ TrW3@@}j
package NetFox; I5,Fh>
FqfeH_-U
)g9qkQ8q
import java.io.*; -u{:39y{n
import java.net.*; ;f\0GsA#
3 a`-_<
q6dq@
public class FileSplitterFetch extends Thread { |rQ;|+.
4m:E:zVn
=v8q
String sURL; //File URL s#ykD{Z
long nStartPos; //File Snippet Start Position (0r6_8e6xv
long nEndPos; //File Snippet End Position ' BpRiN
int nThreadID; //Thread's ID 2#!D"F
boolean bDownOver = false; //Downing is over ~JJv 2
boolean bStop = false; //Stop identical ~p.23G]x
FileAccessI fileAccessI = null; //File Access interface -oj@ c OZ
OB%y'mo7]
lq~n*uwO}t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException N*#SY$!y
{ bZ)Jgz
this.sURL = sURL; F`l1I=;
this.nStartPos = nStart; R0>L[1o
this.nEndPos = nEnd; 2rk_ ssvs
nThreadID = id; 4{TUoI6ii
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (`&g
} _z;N|Xe
9ccEF6o0=
" 1Bn/Q
public void run() LS`Gg7]S
{ y=CemJ[~
while(nStartPos < nEndPos && !bStop) &^Io\
{ /T?['#:r-)
<M=K!k
:Vg,[\I{
try{ 2&M 8Wb#
URL url = new URL(sURL); TUT>*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lH[N*9G(
httpConnection.setRequestProperty("User-Agent","NetFox"); C..O_Zn{g
String sProperty = "bytes="+nStartPos+"-"; F 1BPzRo`
httpConnection.setRequestProperty("RANGE",sProperty); :mij%nQ>$
Utility.log(sProperty); d%<Uh(+:
6i%)'dl
I$YF55uB
InputStream input = httpConnection.getInputStream(); g$ h!:wW
//logResponseHead(httpConnection); ^;'3(m=
~o+u:]
d(tq;2-
byte[] b = new byte[1024]; 3E#acnqn*
int nRead; SpkD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GYBM]mW^ W
{ {_ocW@@
nStartPos += fileAccessI.write(b,0,nRead); Y!KGJ^.mF
//if(nThreadID == 1) ^'}Td~(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~ 60J
} PpbW+}aCF
QDU^yVa_
yY!jkRq%w
Utility.log("Thread " + nThreadID + " is over!"); {pVD`#Tl[
bDownOver = true; yCwQ0|
//nPos = fileAccessI.write (b,0,nRead); I)6)~[:'
} ^ H'|iju
catch(Exception e){e.printStackTrace ();} PS>k67sI
} UXd\Q''
} SgJQH7N
bH&[O`vf
-IPc;`<
//打印回应的头信息 h5F1mr1Sa
public void logResponseHead(HttpURLConnection con) sx6` g;
{ oYu5]ry
for(int i=1;;i++) I` /'\cU9
{ UlyX$f%2
String header=con.getHeaderFieldKey(i); Zf|f $1-
if(header!=null) gbF.Q7?$u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^NP" m
Utility.log(header+" : "+con.getHeaderField(header)); sC/T)q2
else zF{5!b
break; $L?stgU
} &0M^UvO
} U|,VH-#
)5B90[M|t
k*M1m'1
public void splitterStop() Ix"uk6 h
{ p3X>
bStop = true; sURHj&:t|
} DI+kO(S
N1_nBQF )
1h|JKu0
} \ ddbqg?`
0?k/vV4
R7+k=DI
/* &FGz53fd4
**FileAccess.java \ B<(9
*//文件访问(定位，写) kpEES{f
package NetFox; |FH/Q-7[
import java.io.*; koe&7\ _@
RoPz?,u
-]HO8}-Rjs
public class FileAccessI implements Serializable{ EY':m_7W
xj(&EGY:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A:>G:X5t
RandomAccessFile oSavedFile; ~,.Agx
long nPos; s>^*GQw
bc%7-%
W +C\/
public FileAccessI() throws IOException Q']:k}y
{ WC0@g5;1[
this("",0); 3Cq17A 9
} UEt#;e
{V,rWg
9w(QM-u
public FileAccessI(String sName,long nPos) throws IOException P6dIU/w
{ ^<7)w2ns
oSavedFile = new RandomAccessFile(sName,"rw"); $GPenQ~},
this.nPos = nPos; (yn!~El3
oSavedFile.seek(nPos); ]Ocf %(
} |v:8^C7
4, 8gf2
jmz, 1[
public synchronized int write(byte[] b,int nStart,int nLen) J8~3LE )G
{ ZmUS}
int n = -1; OiZPL"Q(K
try{ K'7i$bl%
oSavedFile.write(b,nStart,nLen); Q];+?Pu.
n = nLen; ZoF\1C ^
} K>"M#T
catch(IOException e) rer=o S
{ +kmPQdO;*/
e.printStackTrace (); ^;!A`t
} x=gZ7$?A
ts aD5B
Rq<T2}K
return n; 48Z{wV,
} JIQS'r
%HpTQ
1B}6 zJ
} 8(\Az5%
'cu( Sd}
&Dgho
/* -H#{[M8xX
**SiteInfoBean.java [}N?'foLb
*/ )UO:J7K
package NetFox; 3#j%F
h1:uTrtA
HJ:s)As
public class SiteInfoBean { h)~KD%
% Lhpj[C
kzMCI)>"
private String sSiteURL; //Site's URL %F` cNw]
private String sFilePath; //Saved File's Path %e+hM $Q
private String sFileName; //Saved File's Name =;9Wh!{
private int nSplitter; //Count of Splited Downloading File 50F6jj
D: NBb!
9N:Bu'j&/
public SiteInfoBean() m1heU3BUWU
{//nSplitter的缺省值为5 j*Ta?'*
//default value of nSplitter is 5 f nX!wN
this("","","",5); F<M#T
} 7%c9 nY
U"v(9m@
k3da*vwE
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2G=Bav\n+
{ k"uqso/
sSiteURL= sURL; xa[<k>r3
sFilePath = sPath; Zz'(!h Uy
sFileName = sName; b'pbf
this.nSplitter = nSpiltter; Z2_eTC u
. p^='Kz?
/JaH
} !h4S`2oZ/
Cg?D<l4
<UQaRI[55
public String getSSiteURL() '>^+_|2
{ -v'7;L0K
return sSiteURL; 5?r#6:(yI
} 2asA]sY
'ejuzE9
N)K};yMf
public void setSSiteURL(String value) mT <4@RrB
{ WO?EzQ ?
sSiteURL = value; BNw^ _j1
} >eQ;\j
1mm/Ssw:C
QZ$94XLI
public String getSFilePath() `C%,Nj
{ UTGR{>=>
return sFilePath; GNS5v-"H
} }{[H@uhjH
{a.{x+!5I-
~ ' 81
public void setSFilePath(String value) {mY<R`Ee
{ V@&zn8?
sFilePath = value; z9}rT<hy
} ;{ u{FL
iT1"Le/N
!MSz%QcO
public String getSFileName() .^>[@w3
{ I&l1b>
return sFileName; gQ3Co./
} y8HLrBTza
C18pK8-
H=?v$! i
public void setSFileName(String value) ol^V@3[<
{ k!H;(B"s-
sFileName = value; C(Ujx=G+3
} /tM<ois*
SL" ;\[uI
58,_
public int getNSplitter() `e .;P
{ M7^PWC
return nSplitter; hSSF]
} E]WammX c
VJJGTkm
x tg3~/H
public void setNSplitter(int nCount) '31pb9@fH
{ rVd(H
nSplitter = nCount; FiMP_ y*S
} e;~[PYeu
} `Jhu&MWg
YNA %/
uNZJNrV%
/* }WS%nQA
**Utility.java >DVjO9Kf
*/ 3GUO
package NetFox; ftq&<8
!^cQPX2<
,u^i0uOg
public class Utility { V9z/yNo
mV^+`GWvo
dy N`9
public Utility() &?YbAo_K
{ \g< M\3f
J@C8;]
V^B'T]s
} z #c)Q
<\!+J\YTA
//线程睡眠 Ug*:o d
public static void sleep(int nSecond) li;Np5P
{ !q=ej^(S
try{ w]X~I/6g
Thread.sleep(nSecond); wG[X*/v
} ,2q LiE>
catch(Exception e) F?&n5R.
{ }+G6`Zd
e.printStackTrace (); !:t}8
} fC+<n{"C
} y3@R>@$
GqBZWmAB
//日志 Z12-Vps
public static void log(String sMsg) fiqeXE?E
{ .vYU4g]
System.err.println(sMsg); 1.U5gW/3L
} \E1[ /
|S[Gg
vggyQf%
public static void log(int sMsg) n,}\;Bp
{ (@@t,\iF
System.err.println(sMsg); ' _Ij9{M
} f{MXH&d 1\
} d|CSWcU
N-EVHe'}6
VSP6osX{
/* Z8$n-0Ww
**TestMethod.java Mu$9#[/
*/ CIAHsbn.A
package NetFox; aal5d_Y
<|9s{z
oe`t ? (U
public class TestMethod { =EwC6+8*M
p'z fo!
Lpd q^X
public TestMethod() ee}&~%
{ ///xx/weblogic60b2_win.exe }@%A@A{R
try{ c+$alwL~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); It>8XKS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Hh`x>{,|S
SiteFileFetch fileFetch = new SiteFileFetch(bean); U;f~Q6iu
fileFetch.start(); :E'uV"j%
} uLXMEx<^
catch(Exception e){e.printStackTrace ();} 7\I,;swo
&?C% -"|c
60p*$Vqy
} +I1>; {{
0Snl_@s
X:Z4QqT
public static void main(String[] args) j"o8]UT/
{ x&>zD0\ :\
new TestMethod(); sbn|D\p
} 2VObj7F
} x9S~ns+r
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