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)); pv|Pm
} f{SB1M
for(int i=0;i<nEndPos.length-1;i++) @`\VBW
{ (&/2\0QV
nEndPos = nStartPos[i+1]; }VDqj}is
} wFG3KzEq ~
nEndPos[nEndPos.length-1] = nFileLength; *s@Qtgu
} U qG .:@T
} +`3!I
V_plq6z
+ QQS={
//启动子线程 06jqQ-_`h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; hig2
for(int i=0;i<nStartPos.length;i++) *#TUGfwy
{ .<kqJ|SVi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KNH1#30 K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), v<Bynd-
nStartPos,nEndPos,i); u2 `b'R9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2]%h$f+
fileSplitterFetch.start(); Bl=tYp|a
} 9UvXC)R1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eQQ>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^CwR!I.D}4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [+qCs7'
nEndPos = " + nFileLength); v[Kxja;
// fileSplitterFetch[nPos.length-1].start(); g{5A4|_7
>X*Mio8P#
sz9L8f2
//等待子线程结束 CI3XzH\IX*
//int count = 0; `/Y{ l
//是否结束while循环 yf&7P;A
boolean breakWhile = false; <&)v~-&O
@&[T _l
'\jd#Kn'h
while(!bStop) {Zp\^/
{ asJ)4ema
write_nPos(); L(X6-M:
Utility.sleep(500); KK@.~'d
breakWhile = true; N!*_La=TuH
`^lYw:xA
S_~z-`;h!
for(int i=0;i<nStartPos.length;i++) qCv20#!"|
{ :;t #\%L/
if(!fileSplitterFetch.bDownOver) uc|45Zxt
{ xe/(
breakWhile = false; {rcnM7 S1L
break; =y=cW1TG
} }NsUnbxT
} 4H@Wc^K
if(breakWhile) |HZTN"
break; pmX#E
T?4G'84nN
8i?l02
//count++; .7n\d55a
//if(count>4) *Vho?P6y\Y
// siteStop(); y-CX}B#j
} "?| > btr
o/ui)U_
Y#g4$"G9
System.err.println("文件下载结束！"); \W%UZs
} id$Ul?z8
catch(Exception e){e.printStackTrace ();} 02Ia2e.f
} L\;6y*K
7 [g/TB
P6MRd/y |
//获得文件长度 gzeQ|m2]
public long getFileSize() >MPr=W%E
{ g[w,!F
int nFileLength = -1; JgHM?AWg|
try{ `U2DkY&n
URL url = new URL(siteInfoBean.getSSiteURL()); -j&Tc`j_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ['ksP-=
httpConnection.setRequestProperty("User-Agent","NetFox"); KoS*0U<g6
[d* ~@P
_v* nlc
int responseCode=httpConnection.getResponseCode(); v!%5&: c3
if(responseCode>=400) %TsPyiYl
{ [CAR[ g&
processErrorCode(responseCode); Q:$Zy
return -2; //-2 represent access is error $Y 7c
} {W##^L~
X6^},C'E.:
^ :F.
String sHeader; S(7ro]U9
. BiCBp<
Q);n<Z:X~
for(int i=1;;i++) GIAc?;zY
{ BATG FS&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E#s)52z=B
//Utility.log(in.readLine()); d:F @a
sHeader=httpConnection.getHeaderFieldKey(i); hUm'8)OJ
if(sHeader!=null) d[;.r
{ w4fW<ISg
if(sHeader.equals("Content-Length")) +kFxi2L6
{ ,6r{VLN
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B*E2.\~
break; i<(Xr
} Dr6A,3B
} bBY^+c<
else `8FUX= Sh
break; ZNx$r]4nF
} T,$WlK Wj
} kCXdGhb
catch(IOException e){e.printStackTrace ();} `l*;t`h
catch(Exception e){e.printStackTrace ();} I<A6Z&*un
tlA"B{7
gR@C0
Utility.log(nFileLength); 'ky b\q
n6k9~"?
wM|"I^[
return nFileLength; `~cuQ<3Tn
} 1nu^F,M
}@r{?8Ru
Ve 4u+0
//保存下载信息（文件指针位置） )Jv[xY~
private void write_nPos() kkK kf'
{ t>H`X~SR?
try{ -@ZiS^l
output = new DataOutputStream(new FileOutputStream(tmpFile)); mRZ:ie
output.writeInt(nStartPos.length); ]f1{n
for(int i=0;i<nStartPos.length;i++) YX*Qd$chZ
{ OaL\w D^
// output.writeLong(nPos); 7h)iu9j
output.writeLong(fileSplitterFetch.nStartPos); qL94SW;
output.writeLong(fileSplitterFetch.nEndPos); b pv=%
} m:hY`[ f6
output.close(); ''|#cEc)
} C2{lf^9:&
catch(IOException e){e.printStackTrace ();} D0N9Ksq
catch(Exception e){e.printStackTrace ();} pn*3\
} Q#EP|
Sv;_HZ
m%PC8bf`S
//读取保存的下载信息（文件指针位置） l|hUw
private void read_nPos() #A8@CA^d
{ P/`I.p;
try{ 4GB7A]^E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5?Wto4j
int nCount = input.readInt(); gI8Bx]
nStartPos = new long[nCount]; tbO H#|
nEndPos = new long[nCount]; [7YPl9
for(int i=0;i<nStartPos.length;i++) Dn>%%K@0
{ ,[A'tUl _
nStartPos = input.readLong(); CwX Z
nEndPos = input.readLong(); v|E"[P2e
} 'u` .P:u?
input.close(); {%#)5l)
} 7G)H.L)$m"
catch(IOException e){e.printStackTrace ();} PoIl>c1MS
catch(Exception e){e.printStackTrace ();} 1$*%"5a
} b2@VxdFN
NuU9~gSQ
X(7qZ P~
private void processErrorCode(int nErrorCode) (mlzg=szW
{ )3h^Y=43
System.err.println("Error Code : " + nErrorCode); !s@Rok
} Dk5Zh+^
%e@HZ"V
|!F5.%PY
//停止文件下载 A?G^\I~v
public void siteStop() !yhh8p3
{ aAy'\T$x.
bStop = true; |T{C,"9y
for(int i=0;i<nStartPos.length;i++) 6&bIXy
fileSplitterFetch.splitterStop(); !a~`Bs$'jr
i%6;
SIKOFs
} xTGxvGv8
} z%/N!RLW
//负责部分文件的抓取 smm]6
**FileSplitterFetch.java ]!IVz)<E&
*/ }(<%`G6N
package NetFox; C.kxQ<
~n/ $
*SO{\bu
import java.io.*; +t2SzQ j>
import java.net.*; U?!>Nd
O 1oxZj <
V#jWege
public class FileSplitterFetch extends Thread { F_bF
apk4j\i?5
,<A$h3*
String sURL; //File URL .6OgO{P:
long nStartPos; //File Snippet Start Position !d&C>7nb
long nEndPos; //File Snippet End Position .SWt3|Pi5
int nThreadID; //Thread's ID 2y%,p{="
boolean bDownOver = false; //Downing is over mYc.x
boolean bStop = false; //Stop identical #Oha(mRY
FileAccessI fileAccessI = null; //File Access interface )z8!f}:De=
%0Y=WYUH>
KLX/O1B
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,TRTRb;
{ $#|gLVOQ
this.sURL = sURL; <94_@3
this.nStartPos = nStart; (5Sivw*mP
this.nEndPos = nEnd; IG3,XW
nThreadID = id; $x6$*K(F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Iyo@r%I
} H'qG/@u-l
=YG _z^'
` gW<M
public void run() mm5$> [%U
{ Uje|`<X
while(nStartPos < nEndPos && !bStop) oy<WUb9W
{ +I>p !v
'q * Bdx
:pRpvhm
try{ sK=0Np=`
URL url = new URL(sURL); .ZMW>U>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KQ[!o!%
httpConnection.setRequestProperty("User-Agent","NetFox"); =H<0o?8?c
String sProperty = "bytes="+nStartPos+"-"; JCY~W=;v
httpConnection.setRequestProperty("RANGE",sProperty); 8L*GE
Utility.log(sProperty); 8J)xzp`*)
kcDyuM`
FWC5&tM
InputStream input = httpConnection.getInputStream(); P_u|-~|\
//logResponseHead(httpConnection); f+.T^es
d^(1TNS
CB~Q%QLG
byte[] b = new byte[1024]; M.td^l0
int nRead; S^Au#1e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H[b}kZW:a
{ U}$DhA"r"
nStartPos += fileAccessI.write(b,0,nRead); 4'p=p#o
//if(nThreadID == 1) )fdE6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VGqa)ri"
} irk*~k ?
p*5\+WO>!(
I\|N
Utility.log("Thread " + nThreadID + " is over!"); D=TL>T.bf
bDownOver = true; j6(?D*x
//nPos = fileAccessI.write (b,0,nRead); ,i.%nZw\
} xug)aE
catch(Exception e){e.printStackTrace ();} iRi{$.pVJ
} h3gWOU
} IHC1G1KW=A
:D7|%KK
?GBkqQ
//打印回应的头信息 Z2"?&pKV
public void logResponseHead(HttpURLConnection con) hO[3Z^X
{ US{3pkr;I]
for(int i=1;;i++) +%\oO/4Fs
{ 8j1ekv
String header=con.getHeaderFieldKey(i); UhmTr[&
if(header!=null) gK|R =J
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O--7<Q\
Utility.log(header+" : "+con.getHeaderField(header)); IaFr&
else ;W:6{9m ze
break; oVCmI"'
} I?Q+9Rmm`J
} _7a'r</@
Q:6VYONN
ESb ]}c:
public void splitterStop() yg]2erR
{ zdSh:
bStop = true; 0iEa[G3
} 0@Kkl$O>mb
@/%{15s.
<5@PWrU?[[
} `P@- %T
~2u\
buk=p-oi
/* l2hG$idC
**FileAccess.java wcDjg&:=ml
*//文件访问(定位，写) s~26
package NetFox; +CM7C%U
import java.io.*; f=J<*h
2>em0{e
bl/,*Wx:4.
public class FileAccessI implements Serializable{ ^%y`u1ab
{F|48P;J
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .I$}KE)
RandomAccessFile oSavedFile; si(;y](
long nPos; uHNpfKnZ
A\te*G0:S
8cHE[I
public FileAccessI() throws IOException xn}BB}s{t
{ *@ED}Mj+
this("",0); GbU@BN+_
} ^+?|Qfi
)y7_qxwbV
pJ,@Y>
public FileAccessI(String sName,long nPos) throws IOException ED} 31L
{ K X]oE+:
oSavedFile = new RandomAccessFile(sName,"rw"); i[semo\E
this.nPos = nPos; V:bV ?lt
oSavedFile.seek(nPos); |Y_ -
} `0#H]=$2h
}1+%_|Y-E
b4,jN~ci
public synchronized int write(byte[] b,int nStart,int nLen) K'6[J"dB
{ ,ZI\dtl
int n = -1; IPA*-I57
try{ +yt6(7V*
oSavedFile.write(b,nStart,nLen); ;_<)JqUh
n = nLen; JhR W[~
} ^&c$[~W
catch(IOException e) hv)7H)|l~]
{ Sav`%0q?7a
e.printStackTrace (); 8 |h9sn;P
} N b3$4(F
& 7QH^
8V4V3^_xs
return n; igDyp0t
} A~-#@Z
B94 &elu
dGgP_S
} M:ai<TZ]
m$y]Lf
p {%t q$}.
/* rPq<Xb\
**SiteInfoBean.java #w3ru6*W
*/ VTe.M[:
package NetFox; S-E++f9D~
6 o[/F3`
,&a`d}g&G
public class SiteInfoBean { "2HY5AE
4?]oV%aP)
p4/$EPt)lY
private String sSiteURL; //Site's URL Ae|P"^kZ
private String sFilePath; //Saved File's Path ,J9}.}Hd
private String sFileName; //Saved File's Name 'UDBV
private int nSplitter; //Count of Splited Downloading File r25Z`X Z
Nh)[rx
ekzjF\!y
public SiteInfoBean() Go+[uY^
{//nSplitter的缺省值为5 }_46y*o8
//default value of nSplitter is 5 I 8Y*@$h
this("","","",5); F>Y9o-o2
} /BHepD}
Di??Q_$ak
f?0s &Xo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k7bl'zic
{ lg/sMF>z\f
sSiteURL= sURL; q=Xg*PM,
sFilePath = sPath; A1JzW)B
sFileName = sName; 8@7AE"
this.nSplitter = nSpiltter; q9}2
shi Hy*(v
dl/X."iv!
} 2Ug.:![
kG3!(?:
r#~K[qb
public String getSSiteURL() dm^H5D/A
{ U'3Fou}
return sSiteURL; +0#JnqH"
} Hql5oA
`facFt[\
{fG|_+tl3o
public void setSSiteURL(String value) WV_`1hZX
{ 52<~K
sSiteURL = value; {^&k!H2
} ;mJkqbVol
8gpBz'/,
Tt6{WDscZ
public String getSFilePath() zHxmA
{ 9A;6x$s
return sFilePath; wA0eG@xi)
} o8D{dS>,PL
vw rRZ"2
@6%gIsj<H
public void setSFilePath(String value) w#{l4{X|
{ }GRMZh_8
sFilePath = value; h;n\*[fDc
} jyjQzt >\
^('cbl
G `Izf1B`I
public String getSFileName() |9]PtgQv7
{ ?N#[<kd
return sFileName; 6:RMU
} g3a/;wl
.;%q/hP
/oDpgOn
public void setSFileName(String value) 9qeZb%r&
{ "8t\MKt(
sFileName = value; J8h7e}n?
} B "n`|;r5
rU*q@y Px
9UmBm#"
public int getNSplitter() Y2vj}9jK
{ zv9MHC &
return nSplitter; #J~Xv:LgD
} =5_y<0`4
=L16hDk o
xvO 3BU~2
public void setNSplitter(int nCount) _>Ln@
{ {jG.=}/Dk
nSplitter = nCount; AgI>
} ZV#$Z
} 4@~a<P#
qp1\I$Y
4f jC
/* :tlE`BIp
**Utility.java @{bb'q['@
*/ 5h(jeT8"
package NetFox; u7(];
=f4<({9
x.G"D(
public class Utility { u !.DnKu
ULTNhq R*n
#'g^Za
public Utility() \AJS,QD
{ {0fz9"|U
=?+w)(*0c
wzxdVn 'S
} E4i@|jE~)
`+fk`5Y
//线程睡眠 pDmK
public static void sleep(int nSecond) l<n5gfJ
{ 1 Xa+%n9
try{ wVQdUtmk
Thread.sleep(nSecond); ,$PFI(Whk
} $Br>KJ%'g
catch(Exception e) pzAoq)gg:
{ !(yT7#?hP
e.printStackTrace (); uwId
} rx}*u3x=
} F1\`l{B,\
5Fr;
//日志 3~:0?Zuq
public static void log(String sMsg) dWjx"7^
{ e|~C?Ow'J
System.err.println(sMsg); QK'`=MU
} "]w!`^'_
+>u>`|
h$|3dz N
public static void log(int sMsg) pIvfmIm
{ 3)xbnRk
System.err.println(sMsg); hXPocP
} #_{0Ndp2
} tw-fAMwU
yT&x`3f"i
n{L:MT9TD
/* lD-V9
**TestMethod.java 2aFT<T0
*/ ]ZDTn
package NetFox; #>"}q3RO
2Gm-\o&Td"
fqN75['n
public class TestMethod { "I@v&(Am;
CJm.K
prwC>LE
public TestMethod() P3i^S_
{ ///xx/weblogic60b2_win.exe "*+\KPCU
try{ 8,_ -0_^$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _HLC>pH~#
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 487YaioB$
SiteFileFetch fileFetch = new SiteFileFetch(bean); g;l'VA3v
fileFetch.start(); "bPCOJ[v9
} XzW7eO,A
catch(Exception e){e.printStackTrace ();} .uBO
rAM*\=
u]P03B
} ) b/n)%6
ENO? ;
b~jIv:9T
public static void main(String[] args) epn#qeX
{ !O 4<I_EY{
new TestMethod(); >dyhox2*"
} eN2dy-0
} G l_\Vy
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