http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); J+hifO
} @XKVdtG
for(int i=0;i<nEndPos.length-1;i++) Ftud6
{ _9iF`Q
nEndPos = nStartPos[i+1]; 5Ak>/QF9
} T=pKen/
nEndPos[nEndPos.length-1] = nFileLength; 5*$z4O:Aa
} cW^u4%f't'
} &=.7-iC|W
!/e8x;_
:Ui'x8yt
//启动子线程 v #Q(g/^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TiI3<.a!
for(int i=0;i<nStartPos.length;i++) k)fLJ9R
{ U }}E E~W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `S=4cSH(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2|8$@*-\
nStartPos,nEndPos,i); o7:"Sl2AD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ery{>|k
fileSplitterFetch.start(); 8uetv
} %TQ5#{Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yrrP#F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /KCIb:U
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y@]:7
nEndPos = " + nFileLength); B+=Xb;p8
// fileSplitterFetch[nPos.length-1].start(); IeE6?!,)
8d\/
i}ti
//等待子线程结束 :}fIu?hCA
//int count = 0; K6oQx)|
//是否结束while循环 At8^yF
boolean breakWhile = false; C6}`qD
K>`*JJ,
0Y ld!L
while(!bStop) ? `#
{ 0[SrRpD
write_nPos(); tumYZ)nW
Utility.sleep(500); [c#?@S_
breakWhile = true; e{IwFX
Zk 9i}H
si>gYO
for(int i=0;i<nStartPos.length;i++) +K*_=gHF.
{ uze5u\
if(!fileSplitterFetch.bDownOver) 1FmqNf:V7I
{ H=7Nh6v
breakWhile = false; PsoW:t
break; Sc3B*.
} 7W\aX*]
} _f~m&="T!
if(breakWhile) 3D"?|rd~
break; e't1.%w
8qQrJFm|3*
F6 c1YI[
//count++; ^B7C8YP
//if(count>4) gpzZs<ST
// siteStop(); 9jTm g%
} Hs6}~d
Cu+u'&U!
R?GF,s<j
System.err.println("文件下载结束！"); 2XGbqZj
} b_j8g{/9
catch(Exception e){e.printStackTrace ();} )MJy
} x$\w^h\F
&26H
2k3yf_N
//获得文件长度 iKN800^u
public long getFileSize() h9L/.>CX
{ i7(\i2_P
int nFileLength = -1; [E/}-m6g
try{ hz_F^gF
URL url = new URL(siteInfoBean.getSSiteURL()); &SE+7HXw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |Zrkk>GW:
httpConnection.setRequestProperty("User-Agent","NetFox"); 3teanU`
bkfk9P
5.e. BT
int responseCode=httpConnection.getResponseCode(); {Lm%zdk*k
if(responseCode>=400) LQrm/)4bF5
{ >E3 lY/[
processErrorCode(responseCode); PC}m.tE
return -2; //-2 represent access is error *X4$'LSx1
} k|c=O6GO
^U4|TR6mub
hu+% X.F4
String sHeader; _C97G&
~NtAr1
SMdkD]{g
for(int i=1;;i++) XUyoZl?
{ E@F:U*A6%
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ut xe
//Utility.log(in.readLine()); "gPAxt
sHeader=httpConnection.getHeaderFieldKey(i); )4P5i b
if(sHeader!=null) dnP3{!"b
{ ?~5J!|r#
if(sHeader.equals("Content-Length")) BsX# ~
{ HBFuA.",
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !bHM:!6^
break; %g>{m2o
} H}$hk
} xf.2Ig
else <C'S#5,2
break; Pyx$$cj
} :tA|g
} Uieg4Iro
catch(IOException e){e.printStackTrace ();} [,|Z<
catch(Exception e){e.printStackTrace ();} m9Uoq[1
[[[QBplJ
!I? J^0T
Utility.log(nFileLength); {mp;^/O`er
a'v%bL;H~
4D/mm(2d$
return nFileLength; )^&)f!f
} cg,_nG]i
R<!WW9IM
rGZ@pO2
//保存下载信息（文件指针位置） ~%Ws"1
private void write_nPos() mP)<;gm,
{ _l?5GLl_F$
try{ )W@H
output = new DataOutputStream(new FileOutputStream(tmpFile)); e;=G|E
output.writeInt(nStartPos.length); 7#,+Q(2
for(int i=0;i<nStartPos.length;i++) FVsNOU
{ Kg@9kJB
// output.writeLong(nPos); ubhem(p#
output.writeLong(fileSplitterFetch.nStartPos); 'Ph4(Yg
output.writeLong(fileSplitterFetch.nEndPos); UY**3MK
} Y54*mn
output.close(); utwh"E&W
} Iw"?%k\U
catch(IOException e){e.printStackTrace ();} [,5clR=F
catch(Exception e){e.printStackTrace ();} U gB
} e_6 i896
@fpxGMy&
xiRTp:>
//读取保存的下载信息（文件指针位置） B>47Ic
private void read_nPos() i=2+1;K
{ gr=ke #
try{ O!f*@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c2"eq2'BS
int nCount = input.readInt(); t9pPG{1
nStartPos = new long[nCount]; ]Ly)%a32
nEndPos = new long[nCount]; WaMn[/{
for(int i=0;i<nStartPos.length;i++) l!iB -?'u
{ /gFyow1W
nStartPos = input.readLong(); y+:<
nEndPos = input.readLong(); _k+Bj.L
} !9)*.9[8
input.close(); 1*-58N*
} K0I-7/L
catch(IOException e){e.printStackTrace ();} 1<R \V
catch(Exception e){e.printStackTrace ();} ;U`HvIch
} b'-gy0
[1vrv(u>
.Yu,&HR
private void processErrorCode(int nErrorCode) U |4%ydG
{ hrAI@.Bo
System.err.println("Error Code : " + nErrorCode); orU4{.e
} ^$#Q_Y|
b`:Eo+p
f:utw T
//停止文件下载 Y0hL_46>
public void siteStop() ?y04g u6p
{ )O&$-4gL'
bStop = true; 4*dT|NU
for(int i=0;i<nStartPos.length;i++) oL6_Ya
fileSplitterFetch.splitterStop(); uC;@Yi8
yWK[@;S]%
l/I W"A
} W@0(Y9jdg
} 54)}^ftY^
//负责部分文件的抓取 `H|g~7KD&
**FileSplitterFetch.java &`%C'KZ
*/ :D/R
package NetFox; *LhR$(F(
kB:R-St
-FPl",f=r
import java.io.*; `150$*K&B
import java.net.*; L`p[Dq.
r:o!w7C:a
[lJ[kr*7
public class FileSplitterFetch extends Thread { EagI)W!s[
6$Dbeb
$H9xM
String sURL; //File URL P6?Q;-\q0
long nStartPos; //File Snippet Start Position #nd,cn
long nEndPos; //File Snippet End Position /[-hJ=<Yb
int nThreadID; //Thread's ID >ylVES/V
boolean bDownOver = false; //Downing is over 3A9|{Vaz+6
boolean bStop = false; //Stop identical j?,$*Fi
FileAccessI fileAccessI = null; //File Access interface Tld{b
>w'6ZDA*X
n#R!`*[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ea !j-Lbo
{ St3~Y{aI|
this.sURL = sURL; ,8 .`;
this.nStartPos = nStart; dvf*w:5K!
this.nEndPos = nEnd; (+@.L7>m+t
nThreadID = id; )Qc$UI8L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *Zvw&y*
} R}]FIu
| jkmh6
nk{1z\D{
public void run() *!Dzst-J3
{ N$+"zJmw&
while(nStartPos < nEndPos && !bStop) 0Nfj}sXCWE
{ %|I|Mc
t Z%?vY~!
4>W`XH
try{ K$Ph$P@
URL url = new URL(sURL); ~,:f,FkSQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hG67%T'}A
httpConnection.setRequestProperty("User-Agent","NetFox"); Uwp +w
String sProperty = "bytes="+nStartPos+"-"; QJ/SP
httpConnection.setRequestProperty("RANGE",sProperty); #.@=xhK/
Utility.log(sProperty); o6r4tpiR5
`#]\Wnp~y
fS~.K9
InputStream input = httpConnection.getInputStream(); 1m0':n Vdu
//logResponseHead(httpConnection); f.= E.%
(X9V-4
40<&0nn
byte[] b = new byte[1024]; u%pief
int nRead; 8%4`Yj=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) EI;\of2,
{ t'J fiGM
nStartPos += fileAccessI.write(b,0,nRead); }:%pOL n
//if(nThreadID == 1) VtO+=mZV
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X_qXH5^%
} {G}HZv%S U
,uv$oP-
Yx"z&J9p
Utility.log("Thread " + nThreadID + " is over!"); --9mTqx
bDownOver = true; =%3nKSg
//nPos = fileAccessI.write (b,0,nRead); _=8+_OEk
} T)uw2
catch(Exception e){e.printStackTrace ();} ]ok>PH]
} 1@WGbORc*
} +@Y[i."^J
I?K0bs+6
cGp^;> ]M
//打印回应的头信息 q0~_D8e,
public void logResponseHead(HttpURLConnection con) ~K9U0ypH
{ .*j+?
for(int i=1;;i++) 2]+.8G7D%
{ -)oBh
String header=con.getHeaderFieldKey(i); a5-\=0L~
if(header!=null) T?Y\~.+99
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _#C}hwOR>X
Utility.log(header+" : "+con.getHeaderField(header)); -?W@-*J
else {#,FlR2
break; +2SX4Kxu
} Iqsk\2W]a3
} qC)VT3
.N=hA
qj&)w9RLJE
public void splitterStop() *3$,f>W^
{ HhvG#Sam!
bStop = true; {<kG{i/
} Z=0W@_s
=FmU]DV
x/=j$oA
} PlZiTP
K_QCYS.
[Ni4[\
/* Y9;Mey*oW
**FileAccess.java ?_aR-[XRg
*//文件访问(定位，写) spJ(1F{|V
package NetFox; Q$1K{14I
import java.io.*; Nd!VR+IZ
vi8~j
j;)g+9`
public class FileAccessI implements Serializable{ zc+;VtP|8
>A&@Wp1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F-^HN%
RandomAccessFile oSavedFile; yf)`jPM1<
long nPos; -`OR6jd
91H0mP>ki
3J T3;O
public FileAccessI() throws IOException U[b;#Y1X
{ _m],(J=,z
this("",0); (x qA.(F
} Jj:6 c
\w^QHX1+
FRFAWK<
public FileAccessI(String sName,long nPos) throws IOException 2HXKz7da
{ d|]O<]CG_
oSavedFile = new RandomAccessFile(sName,"rw"); K;[%S
this.nPos = nPos; rf->mk{
oSavedFile.seek(nPos); f_ztnRw
} /y)"j#-eW
|A0$XU{
pm]DxJ@
public synchronized int write(byte[] b,int nStart,int nLen) .KucjRI
{ LUck>l\l
int n = -1; wy{>gvqK
try{ ,g_onfY
oSavedFile.write(b,nStart,nLen); oDP((I2-
n = nLen; </gp3WQ.
} AwUc{h l<
catch(IOException e) \oX8/-0f
{ 9T2A)a]0
e.printStackTrace (); zpqGh
} )7GLS\uf<%
WEtA4zCO
@b\ S.
return n; .vS6_
} 1?|6odc
b$O_L4CP
9K':Fn2,
} RX5.bVp eE
kLt9;<L
;#s}b1
/* liqR#<
**SiteInfoBean.java k0_$M{@Y
*/ qQOD
package NetFox; _1<'"u#6w
,|X+/|gm
3g[j%`k
public class SiteInfoBean { 6@q[tN7_^
oL'1Gm@X?
.3<IOtD=
private String sSiteURL; //Site's URL ie@`S&.8 T
private String sFilePath; //Saved File's Path ?[VpN2*
private String sFileName; //Saved File's Name $[iT~B$
private int nSplitter; //Count of Splited Downloading File ]A72)1
^qO=~U!{
!UoU#YU
public SiteInfoBean() Zknewv*sS4
{//nSplitter的缺省值为5 C$LRY~\
//default value of nSplitter is 5 !I5~))E
this("","","",5); RP,:[}mPl
} H [Lt%:r
ouVjZF@kS
;,=h59`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F|?'9s*;6G
{ :e]9T3Q
sSiteURL= sURL; wB>S\~i
sFilePath = sPath; <*"pra{3
sFileName = sName; OR\DTLIl
this.nSplitter = nSpiltter; pEVgJ/>
#[a"%byTR
) wY!/&
} g&+Y{*Gp
qC1U&b#MVx
H5rPq_R
public String getSSiteURL() P:(EU s}0
{ .L7Yf+yFg
return sSiteURL; N3gNOq&
} 0UGiPH,()
d"I28PIS"
'DzBp
public void setSSiteURL(String value) 8.CKH4h
{ f[Fgh@4cj
sSiteURL = value; )W]>\=@Y
} N pXgyD
wfDp,T3w7
lMwk.#
public String getSFilePath() [.;%\>Qk<
{ Kr/h`RM
return sFilePath; N(:nF5>_
} 4e@&QOo`Cu
H+VO.s.a
_7lt(f[S
public void setSFilePath(String value) HX3D*2v":
{ ],\sRQbv&
sFilePath = value; wKk 3)@il
} hu P^2*c
&^&$!Xmu9
[O7w =
public String getSFileName() {b'}:aMc
{ hG3m7ht
return sFileName; A{z>D`d
} 3+(yI 4
]eYd8s+
xN`r4
public void setSFileName(String value) aGB0-;.t7
{ JFRpsv
sFileName = value; -J"qrpZ^
} QSHJmk 6L
N^h|h
'7Mep ]
public int getNSplitter() t/KcXM
{ Ak5[PBbW
return nSplitter; d&[iEU
} AozmO
@sw9A93A
Y^R?Q'
public void setNSplitter(int nCount) {gFAvMj#
{ %/l-A pu
nSplitter = nCount; $A;7Em
} C}b|2y
} #y=ZP:{:t
R2}kz.
%n05Jitl
/* @up&q
**Utility.java 7 9Qc`3a
*/ 2J;kD2"!
package NetFox; tYs8)\{
.P)s4rQ\
t_jyyHxoZ:
public class Utility { N[qA2+e$Z
n1QEu"~Zj
`d7gm;ykp
public Utility() @B,j;2eb
{ o'C~~Vg).
t=n+3`g
ud0QZ X
} {TyCj?3B
1.'(nKoq
//线程睡眠 |DN^NhtE
public static void sleep(int nSecond) fy&#M3UA\U
{ )@}A r
try{ }m6f^fs}
Thread.sleep(nSecond); ?gLR<d_
} [IiwNqZ[~
catch(Exception e) ,YjxCp3
{ u`'ki7LA
e.printStackTrace (); >M?H79fF2s
} Q_ctX|.
} $hh+0hs
8h2D+1,PZC
//日志 _ XE;-weE
public static void log(String sMsg) `-VG ?J
{ w6vLNX
System.err.println(sMsg); fO K|:
} b-PSm=`
1p8:.1)q
k+FMZ,D|
public static void log(int sMsg) Le*`r2
{ 0|g[o:;fl_
System.err.println(sMsg); WtIMvk
} }N?g|
} wHx}U M"
:^n*V6.4
YWEYHr;%^?
/* 6`acg'sk>
**TestMethod.java o`idg[l.
*/ (Aorx #z
package NetFox; P{?;T5ap6
G'u|Q mb1
'e F%
public class TestMethod { `M&P[.9Pz
5J ySFG3
Ua %UbAt
public TestMethod() [w!C*_V 9
{ ///xx/weblogic60b2_win.exe G\R*#4cF
try{ T/ik/lFI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KYp[Gs
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iQqqs`K
SiteFileFetch fileFetch = new SiteFileFetch(bean); tww=~!
fileFetch.start(); $]C=qM28-
} wh%xkXa[ur
catch(Exception e){e.printStackTrace ();} lr,q{;
Z:!IX^q;}n
Mm5c8[
} )i;un.
_6ZzuVv3/
.46#`4av
public static void main(String[] args) vv+km+
{ }MP>]8Aq
new TestMethod(); ;`DD}j`
} n+2%tW
} vDsF-u1
点击下载更多相关资料