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)); *'?V>q,
} 1}Guhayy
for(int i=0;i<nEndPos.length-1;i++) GB Vqc!d
{ 3xRn
nEndPos = nStartPos[i+1]; a;a1>1
} *yHz#u'
nEndPos[nEndPos.length-1] = nFileLength; R4b!?}d
} *Cp:<Mnd
} DGTE#?'(
XL44pE m
2zbn8tO
//启动子线程 J!|R1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L)<~0GcP
for(int i=0;i<nStartPos.length;i++) M%$ITE
{ h'GOO(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Myn51pczl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), F(/Ka@
nStartPos,nEndPos,i); eC<?g
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S&&QU#
fileSplitterFetch.start(); kZ6:=l
} 1:yil9.\*
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #y"LFoJn
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (i\{hq/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OrL4G `O
nEndPos = " + nFileLength); Z6-
// fileSplitterFetch[nPos.length-1].start(); YIIc@)
ew,okRCN
UHk)!P>
//等待子线程结束 cM,g,E}
//int count = 0; `2\:b^h
//是否结束while循环 7$Wbf4
boolean breakWhile = false; ?MfwRWY
![4_K':=
4\ElMb[]
while(!bStop) .=yv m
{ n``9H91
write_nPos(); #RyTa /L
Utility.sleep(500); ugj I$u
breakWhile = true; 2[1t )EW
F.@|-wq&
p1.3)=T
for(int i=0;i<nStartPos.length;i++) B7Zi|-F
{ +~:OUR*>
if(!fileSplitterFetch.bDownOver) b&Laxki
{ -2u)orWP
breakWhile = false; 9D,!]
break; 8N |K
} +Y;hVcE9
} 1A* "v
if(breakWhile) "&`>+Yw
break; m;1/+qs0
9s7TLT k
6Z=Qs=q
//count++; e_l|32#/
//if(count>4) 7hLh}
// siteStop(); >o3R~ [
} E{^W-
a3A3mBw
sk:B;.z
System.err.println("文件下载结束！"); v>mK~0.$
} u"wWekB
catch(Exception e){e.printStackTrace ();} %h,&ND
} (F3R!n
@A`j Wao
c/j+aj0.v
//获得文件长度 6kAGOjO
public long getFileSize() @w(|d<5l:L
{ KLuOg$i
int nFileLength = -1; z6,E}Y
try{ e^x%d[sU
URL url = new URL(siteInfoBean.getSSiteURL()); '.gi@Sr5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $-jj%kS
httpConnection.setRequestProperty("User-Agent","NetFox"); DvLwX1(l
qu'D"0
bI(8Um6m
int responseCode=httpConnection.getResponseCode(); XWNo)#_3
if(responseCode>=400) 2AMb-&po&f
{ k!bJ&} Q(b
processErrorCode(responseCode); 35x]'
return -2; //-2 represent access is error }J-e:FUF#
} 1_;{1O+B
*(5T?p[7
~4twI*f
String sHeader; C9""sVs
darbL_1
Z.x]6
for(int i=1;;i++) <Ter\o5%
{ Jt<J#M<}7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C(8!("tU
//Utility.log(in.readLine()); ?<\2}1
sHeader=httpConnection.getHeaderFieldKey(i); kkMChe};5
if(sHeader!=null) to1r 88X
{ 3` D['
if(sHeader.equals("Content-Length")) 1{a4zGE?[
{ DWCf+4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); suFk<^3
break; JBZ1DZAWC
} 0jPUDkH*
} 6V@_?a-K
else zKaj<Og
break; T5I#7LN#
} 0V^I.S/q
} B(} 'yY@%u
catch(IOException e){e.printStackTrace ();} X8R:9q_
catch(Exception e){e.printStackTrace ();} Zu>-y#Bw
Z#^|h0
JY;u<xl
Utility.log(nFileLength); JR&yaOws
-XK;B--c
Ho[]03
return nFileLength; ]|=`-)AP3
} FgrVXb_q
7&%HE\
{X_I>)Wg
//保存下载信息（文件指针位置） 9HlWoHuC
private void write_nPos() a'n17d&
{ dV}]\8N
try{ \1n (Jr.<
output = new DataOutputStream(new FileOutputStream(tmpFile)); 9Nx%Sdu
output.writeInt(nStartPos.length); ]w$cqUhM
for(int i=0;i<nStartPos.length;i++) \d]Y#j<
{ $<&_9T#&w
// output.writeLong(nPos); G%zJ4W%
output.writeLong(fileSplitterFetch.nStartPos); UWK|_RT6SA
output.writeLong(fileSplitterFetch.nEndPos); kCoE;)y$
} _IV!9 JL
output.close(); q"DHMZB
} z}Us+>z+jc
catch(IOException e){e.printStackTrace ();} #T{)y
catch(Exception e){e.printStackTrace ();} ^Oeixi@f
} v]H9`s#,
MA}}w&
>LN*3&W
//读取保存的下载信息（文件指针位置） ._<, Eodv
private void read_nPos() s1#A0%gx
{ bKzG5|Qu
try{ D&G?Klq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #Ak|p#7 ^
int nCount = input.readInt(); 1wdc4>
nStartPos = new long[nCount]; ' u;Zw%O(J
nEndPos = new long[nCount]; qdmAkYUC
for(int i=0;i<nStartPos.length;i++) yJ ljCu)f
{ SyT{k\[
nStartPos = input.readLong(); 8t)gfSG
nEndPos = input.readLong(); 1w7XM0SHcn
} %B1)mA;
input.close(); "M\rO!f:
} g>w {{G
catch(IOException e){e.printStackTrace ();} ?E}gm>
catch(Exception e){e.printStackTrace ();} )UTjP/\gN
} ?$uF(>LD
_Ex<VF u
w:iMrQeJg
private void processErrorCode(int nErrorCode) r ?<kWR?w
{ Q>9bKP
System.err.println("Error Code : " + nErrorCode); %X}vuE[[UC
} 1;i|GXY:h
4GG>n
^;9l3P{
//停止文件下载 ur=:Ha
public void siteStop() mW+5I-~
{ 0 z]H=
bStop = true; YktZXc?iI<
for(int i=0;i<nStartPos.length;i++) j72mm!
fileSplitterFetch.splitterStop(); VlSM/y5
jvD_{r
z 0zB&}
} )PYh./_2
} Gm9
//负责部分文件的抓取 9ZatlI,
**FileSplitterFetch.java J4U_utp
*/ G51-CLM,
package NetFox; Tp.]{*
.3VL
@p}_"BHYWt
import java.io.*; %hw4IcWJ|
import java.net.*; 9^`cVjD5
&,:!gYN
>&R@L KP
public class FileSplitterFetch extends Thread { *//z$la
`kv7Rr}Q
\/gf_R_GN
String sURL; //File URL U>bIQk"4
long nStartPos; //File Snippet Start Position 'irwecd8
long nEndPos; //File Snippet End Position ` "-P g5
int nThreadID; //Thread's ID skTaIGRL
boolean bDownOver = false; //Downing is over r$'.$k\
boolean bStop = false; //Stop identical ]@Z nP,8
FileAccessI fileAccessI = null; //File Access interface ,O:p`"3`0=
1ah,Zth2
@,;h!vB*=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m|x_++3
{ |`Yn'Mj8rm
this.sURL = sURL; {Oq8A.daJ
this.nStartPos = nStart; "UhE'\()
this.nEndPos = nEnd; A #m_w*
nThreadID = id; 8t, &dq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RW1+y/#%P
} T5e#Ll/
R^sgafGl=
)Y'g;
public void run() ZNk[Jn [.
{ {hN<Ot
while(nStartPos < nEndPos && !bStop) !7Qj8YmS
{ IR:{{ (
I@O9bxR?
8'bZR]
try{ JC~4B3!
URL url = new URL(sURL); Mqk|H~l5c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M"{*))O\-c
httpConnection.setRequestProperty("User-Agent","NetFox"); tq@)J_7|
String sProperty = "bytes="+nStartPos+"-"; eY^zs0
httpConnection.setRequestProperty("RANGE",sProperty); F2_'U' a
Utility.log(sProperty); <exyd6iI
>SziRm>Y7
^`aw5 +S
InputStream input = httpConnection.getInputStream(); \Ucv<S
//logResponseHead(httpConnection); =2DK?]K;
'+j;g
tlg}"lY
byte[] b = new byte[1024]; u2$.EM/iae
int nRead; aaN/HE_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .3n\~Sn
{ ydY 7 :D
nStartPos += fileAccessI.write(b,0,nRead); $UK m[:7
//if(nThreadID == 1) |22vNt_
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `'EG7
} tl7:L>
^;( dF<?'r
4b`Fi@J\
Utility.log("Thread " + nThreadID + " is over!"); =ud~
bDownOver = true; %hZX XpuO
//nPos = fileAccessI.write (b,0,nRead); kq?:<!z
} G/fBeK$.
catch(Exception e){e.printStackTrace ();} }Y!s:w#
} xN}f?
} q@XJ,e1A
w'$>E4\
(vzYgU,
//打印回应的头信息 ~&F|g2:
public void logResponseHead(HttpURLConnection con) _y>drvg
{ *<SXzJ(
for(int i=1;;i++) yM9>)SE5`
{ ~UQ<8`@a
String header=con.getHeaderFieldKey(i); 5!$sQ@#}D
if(header!=null) v,ni9DIu
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O7LJ-M
Utility.log(header+" : "+con.getHeaderField(header)); -b8SaLak
else VYh/URU>
break; (4yXr|to}
} d7QUg6=
} @(E6P;+{
GE=S.P;
{%^4%Eco
public void splitterStop() qxHn+O!h
{ m?Cb^WgcF
bStop = true; Oj_F1. r
} )^4Ljb1
pr4y*!|Y$
-a~n_Z>_
} KU0Ad);e
q(hBqUW
9kqR-T|Q
/* \dE{[^.5
**FileAccess.java OK`^DIr5l
*//文件访问(定位，写) PvjZoF["
package NetFox; `U\l: ~]e
import java.io.*; UGgo;e
KC2Z@
9xw"NcL
public class FileAccessI implements Serializable{ dBovcc
7^M$u\a)U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 V:P]Ved
RandomAccessFile oSavedFile; |S@
long nPos; #8M^;4N>[
Z(R0IW
hy%5LV<(
public FileAccessI() throws IOException Vjo[rUW
{ :7obxW1X
this("",0); =ONM#DxH
} *mWl=J;u
gN[t
J]S30&?
public FileAccessI(String sName,long nPos) throws IOException S*J\YcqSC
{ ]>k8v6*=
oSavedFile = new RandomAccessFile(sName,"rw"); ycOnPTh
this.nPos = nPos; #<sK3PT
oSavedFile.seek(nPos); !T ,=kh
} !^0vi3I
`Je1$)%
QOrMz`OA
public synchronized int write(byte[] b,int nStart,int nLen) g=qaq
{ /iQh'rp
int n = -1; J>;r(j
try{ `r3 klL,W'
oSavedFile.write(b,nStart,nLen); bXXX-Xc
n = nLen; gYk5}E-
} ;YMg4Cs
catch(IOException e) R;A8y
{ ?P>4H0@I+
e.printStackTrace (); u#^l9/tl
} iPWr-
w{*V8S3h9
@o'L!5Y
return n; 9h)8Mq+M
} :~srl)|)
3ZyvX]@_
v+79#qWK|n
} c9CFGo?)N
.;ofRx<
jJt4{c
/* CH|cK8q
**SiteInfoBean.java 5M5vxJ)Lh
*/ |/%5~=%7
package NetFox; fB,eeT1v?h
$ywROa]
9b,0_IMHH
public class SiteInfoBean { 8tna<Hx
/7p(%vr
41+WIa L
private String sSiteURL; //Site's URL l`:u5\ rM
private String sFilePath; //Saved File's Path X%(NI(+x,
private String sFileName; //Saved File's Name Ej6ho0_
private int nSplitter; //Count of Splited Downloading File @)[8m8paV
R)*l)bpZ#
p$jAq~C
public SiteInfoBean() _JTK$\
{//nSplitter的缺省值为5 (aSuxl.Dq
//default value of nSplitter is 5 zF{~Md1
this("","","",5); K`<HZK
} WwtVuc|
wpi$-i`
P6ktA-Hv>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) f5un7,m
{ R2C~.d_TDu
sSiteURL= sURL; .7LQ l?
sFilePath = sPath; d]^m^
sFileName = sName; _~C1M&b(X3
this.nSplitter = nSpiltter; *!*%~h8V
XE2rx2k
.oTS7rYw
} t)?K@{ 9
Y`4 LMK[]
J=: \b
public String getSSiteURL() |s(Ih_Zn
{ 6J}Yr5oD
return sSiteURL; 6vps`k$,~
} nHq4f&(H
+,$pcf<[V
KfZb=v;-l
public void setSSiteURL(String value) YX)Rs Vf
{ r@vt.t0#
sSiteURL = value; XOI"BLd
} )rAJ>;
.j^BWr
T{m) = (q
public String getSFilePath() $0un`&W
{ nTwJR
return sFilePath; 8Lx1XbwK
} "$o>_+U
qnWM %k
-OU{99$aS
public void setSFilePath(String value) (y&sUc9
{ B9$f y).Gp
sFilePath = value; 'kY/=*=Q
} / j%~#@
Meep
*l"CIG'
public String getSFileName() zn&ZXFgN
{ ePJ_O~c
return sFileName; GbZ~eI`,2
} WcY_w`*L
42 lw>gzr!
zy"k b
public void setSFileName(String value) L]!![v.VY
{ #ley3rJW]
sFileName = value; !!V1#?0jw
} -Q JPJ.
v7KBYN
{7]maOg>7J
public int getNSplitter() *) T"-}F
{ v@q&B|0
return nSplitter; .|hsn6i/-
} |3T2}ohrr
[+R_3'aK
1i~q~O,
public void setNSplitter(int nCount) pOn&D
{ hxM{}}.E
nSplitter = nCount; b)e;Q5Z(.
} zp}pS2DU
} ]adgOlM
"-X8
s2|.LmC3|B
/* S1Od&v[R
**Utility.java K?!W9lUq
*/ _E'}8.#{
package NetFox; V]+y*b.60
cHT\sJo`l
y {Bajil
public class Utility { 6jgP/~hP>N
"9QZX[J|*
\~+b&
public Utility() !uIY,
{ vWM&4|Q1~
0,0Z!-Y
,Zb
} A[7H-1-
TlkhI
//线程睡眠 kp<Au)u
public static void sleep(int nSecond) 2YY4 XHQS
{ qpCaW0]7
try{ aQ\SV0PI
Thread.sleep(nSecond); h%W,O,K/
} ji\LC%U-
catch(Exception e) r nr-wUW@
{ mTWd+mx
e.printStackTrace (); )8#-IXxp
} #5{xWMp/0
} KU oAxA
>bQOpGy}l
//日志 c*E7nc)u
public static void log(String sMsg) \mJR^t
{ ~1}fL 1~5
System.err.println(sMsg); D86F5HT}}
} U\qbr.<
b1i~F45h
e Ru5/y~
public static void log(int sMsg) HK<S|6B7V
{ u pUJF`3
System.err.println(sMsg); 26k~Z}
} O#18a,o@
} &g23tT#P?
Fv %@k{
gzSm=6Qw0
/* ocK4Nxs
**TestMethod.java Ij.mLO]
*/ u t4:LHF
package NetFox; K39I j_3
/.!&d^
>yP>]r+
public class TestMethod { F02TM#Zi
O|=?!|`o
@d|Sv1d%
public TestMethod() (2L,m
{ ///xx/weblogic60b2_win.exe C(B"@
try{ Q$]1juqg
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GBRiU&D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /|UbYe,
SiteFileFetch fileFetch = new SiteFileFetch(bean); oPaoQbR(A
fileFetch.start(); +4T.3Njjn
} F}meKc?a
catch(Exception e){e.printStackTrace ();} hrzxc4,W
>yT1oD0+x
^q/^.Gf
} ,P`GIGvkA
^b|? ?9&
+MaEet
public static void main(String[] args) GeB&S!F
{ ?f'`b<o
new TestMethod(); Et-|[ eL
} jCNR63/
} Nb_Glf
点击下载更多相关资料