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)); CX&yjT6`
} eZN3H"H
for(int i=0;i<nEndPos.length-1;i++) 7]M,yIwc
{ ?)Czl4J
nEndPos = nStartPos[i+1]; &xGfkCP.]
} z:ru68
nEndPos[nEndPos.length-1] = nFileLength; <B]i80.
} Dyouk+08x
} 1jUhG2y
rZ8Y=) e
@\%)'WU
//启动子线程 3PvZ_!G
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P`Hd*xh".j
for(int i=0;i<nStartPos.length;i++) zCBtD_@
{ /XWPN(JC?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [#hl}q(P#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4pfix1F g
nStartPos,nEndPos,i); `mq4WXO\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vq .!(x
fileSplitterFetch.start(); Kc JP^
} ]v^`+s}3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bMqu5G_q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1^x2WlUm4
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E&iWtwkz
nEndPos = " + nFileLength); =M/UHOY
// fileSplitterFetch[nPos.length-1].start(); .gM>FUH3L
e_>rJWI}
o-Q]Dk1W
//等待子线程结束 Ww'TCWk@
//int count = 0; r?5@Etpg
//是否结束while循环 Uf7F8JZmM
boolean breakWhile = false; <\}Y@g8
fcE/
.UT,lqEkv
while(!bStop) <iXS0k
{ b2}QoJ@`
write_nPos(); #czyr@
Utility.sleep(500); -~<q,p"e
breakWhile = true; 5,0wj0l
Ry8WNVO}R
d}wa[WRv
for(int i=0;i<nStartPos.length;i++) =& Tu`m
{ 6uCk0 B|
if(!fileSplitterFetch.bDownOver) 7'{Yz
{ r'9=kx
breakWhile = false; Y6;0khp
break; =XacG}_
} |oBdryi
} a!0?L0_W&
if(breakWhile) 7/D9n9F
break; _M"$5 T
2#n$x*CY
ZHiICh|et%
//count++; uhw5O9
//if(count>4) Eis%)oE
// siteStop(); `jUS{ 3^
} B(en5|
\[IdR^<YM
+%Bf y4F6
System.err.println("文件下载结束！"); WB=<W#?w7%
} ?G>5 D`V
catch(Exception e){e.printStackTrace ();} nIT^'
} Kc9mI>uH
~G{$P'[
WnJLX ^;
//获得文件长度 I?>-
public long getFileSize() #)PGQ)(
{ 6XOpB^@
int nFileLength = -1; zNsL^;uT
try{ -X&!dV:= 4
URL url = new URL(siteInfoBean.getSSiteURL()); J++sTQ(!?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AG$-U2ap
httpConnection.setRequestProperty("User-Agent","NetFox"); a_pCjG89
llZ"uTK\M
DETajf/<F
int responseCode=httpConnection.getResponseCode(); Z|Lh^G
if(responseCode>=400) ];b!*Z
{ :i,c<k
processErrorCode(responseCode); H%NLL4&wu
return -2; //-2 represent access is error 9$Pl'>5
} F'5d\v
[#Nx>RY
n7,6a
String sHeader; ~U7\ LBF
:S+U}Sm[
?^yh5
for(int i=1;;i++) uu@'02G8
{ YW$x:
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); M;p q2$
//Utility.log(in.readLine()); [BZ(p
sHeader=httpConnection.getHeaderFieldKey(i); T24#gF~
if(sHeader!=null) E?m#S
{ @rK>yPhf
if(sHeader.equals("Content-Length")) C>\!'^u1
{ QnP?;
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2p3u6\y
break; q| =q:4_L
} |Z7bd^
} t~<-4N$(
else @'<j!CqQ o
break; 1[gjb((
} P{i8
} <k-@R!K~JC
catch(IOException e){e.printStackTrace ();} U70@}5!
catch(Exception e){e.printStackTrace ();} [q>i
MY<!\4/
$jeDVH
Utility.log(nFileLength); (fGJP*YO
SVs~,
xwH|ryfs,Z
return nFileLength; 6dS1\Y
} _@~kYz
FUqhSW
<C.$Db&9
//保存下载信息（文件指针位置） oIL+@}u7
private void write_nPos() qiKtR
{ 5.K$ X$+7}
try{ ETWmeMN
output = new DataOutputStream(new FileOutputStream(tmpFile)); #PLB$$
output.writeInt(nStartPos.length); w`#0 Y9O
for(int i=0;i<nStartPos.length;i++) m/F(h-?
{ Zz)oMw
// output.writeLong(nPos); !K^kKP*l
output.writeLong(fileSplitterFetch.nStartPos); NX{-D}1X=
output.writeLong(fileSplitterFetch.nEndPos); }Mb'tGW
} _F|_C5A
output.close(); p4t!T=o/
} 2wuW5H8w{
catch(IOException e){e.printStackTrace ();} KlqJEtO_
catch(Exception e){e.printStackTrace ();} @8M2'R\
} WPp\sIP
zRJKIm
O->(9k<
//读取保存的下载信息（文件指针位置） 'ZZWH
private void read_nPos() $:gSc&mx
{ C(|T/rQ-
try{ K9N0kBJ0<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >->xhlL*
int nCount = input.readInt(); >*i8RqU
nStartPos = new long[nCount]; #2vG_B<M)
nEndPos = new long[nCount]; HAUTCX
for(int i=0;i<nStartPos.length;i++) -IsdU7}
{ (zYSSf!I
nStartPos = input.readLong(); K"6+X|yxE
nEndPos = input.readLong(); gS<{ekN
} pS@VLXZP
input.close(); gK#fuQ$hH
} x<y[na
catch(IOException e){e.printStackTrace ();} -2na::<K
catch(Exception e){e.printStackTrace ();} bZ22O"F
} QGz3id6
pQMpkAX
H.mQbD`X
private void processErrorCode(int nErrorCode) @61N[
{ _BLSI8!N@
System.err.println("Error Code : " + nErrorCode); ;YXrG
} {6y.%ysU
Q.E^9giC
p$o&dQ=n[
//停止文件下载 [qD<U%Hi
public void siteStop() "T1#*"{j
{ >Hzb0N!VJ
bStop = true; t?H;iBrpxd
for(int i=0;i<nStartPos.length;i++) nTy,Jml
fileSplitterFetch.splitterStop(); 8YLZ)k'
t5v)6|
GH+FZ (F
} *rFbehfH
} )%@WoBRj
//负责部分文件的抓取 A8Z?[,Mq!
**FileSplitterFetch.java kR~4O$riG
*/ mF:s-+
package NetFox; ABe^]HlH
lGHu@(n<
{ugKv?e;
import java.io.*; *9{Wn7pck/
import java.net.*; ihY^~
ecI 2]aKi
Qnb?hvb"d
public class FileSplitterFetch extends Thread { +ET
T&MS_E&;
M*@aA XM
String sURL; //File URL QDT{Xg*I
long nStartPos; //File Snippet Start Position T2_#[bk*d
long nEndPos; //File Snippet End Position OO+#KyU
int nThreadID; //Thread's ID Jq<`j<'9
boolean bDownOver = false; //Downing is over CJtjn
boolean bStop = false; //Stop identical `1}?{ud
FileAccessI fileAccessI = null; //File Access interface `iayh
wOkJ:k
{UC<I.5X
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RTA=|q
{ 'CAukk|
this.sURL = sURL; i|{nj\6w^
this.nStartPos = nStart; -/2$P
this.nEndPos = nEnd; ;)pV[3[
nThreadID = id; 4bi\$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |laKntv2
} MkGq%AE`Y
V42*4hskL
?CZD^>6
public void run() 8]MzOGB8
{ NITx;iC
while(nStartPos < nEndPos && !bStop) H;Qn?^
{ q]%bd[zkz
Fsj&/: q
vA-p}]%
try{ Fj('l
URL url = new URL(sURL); jz7ltoP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <Jrb"H[T"
httpConnection.setRequestProperty("User-Agent","NetFox"); u#,'ys
String sProperty = "bytes="+nStartPos+"-"; U5$DJ5>8
httpConnection.setRequestProperty("RANGE",sProperty); sP8&p*TJF
Utility.log(sProperty); yrNc[kS/
f\r4[gU@
[ .uaO
InputStream input = httpConnection.getInputStream(); vFC=qLz:
//logResponseHead(httpConnection); M`fXH 3D
/lQ0`^yB
v/+}FS=
byte[] b = new byte[1024]; (Tb0PzA
int nRead; |ylTy B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B(Q.a&w45t
{ {u6fa>R&$
nStartPos += fileAccessI.write(b,0,nRead); Q~!hr0 ZR
//if(nThreadID == 1) `e=n(D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `'.x*MNF
} .eXA.9|jm
'J0s%m|j
hg=G//
Utility.log("Thread " + nThreadID + " is over!"); w$:)wyR-
bDownOver = true; =usDI<3r
//nPos = fileAccessI.write (b,0,nRead); _`[6jhNa!
} #$B,8LFz,$
catch(Exception e){e.printStackTrace ();} yzR=:0J
} Kf^F#dA
} ZDJWd=E
KY&,(z
v+bjC
//打印回应的头信息 koY8=lh/
public void logResponseHead(HttpURLConnection con) q0Lt[*q3R
{ o(NyOC
for(int i=1;;i++) tsVhPo]e0
{ cB=u;$k@*
String header=con.getHeaderFieldKey(i); 3CPOZZ
if(header!=null) Ic!83-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 2]*~1d
Utility.log(header+" : "+con.getHeaderField(header)); rh&Eu qE%
else L;7mt 4H
break; nKkTnTSa
} c7!`d.{90
} Cbvl( (
ts!aKx
w=o m7%J@l
public void splitterStop() EXzNehO~e
{ [IA==B7
bStop = true; lA 0_I"b2Y
} L([>yQZ
=,G(1#
A8(PI)Ic.
} qk1D#1vl
6mpUk.M"
#h|< >
/* \9zC?Cw
**FileAccess.java yP]W\W'
*//文件访问(定位，写) OBQ!0NM_b
package NetFox; {;M/J
import java.io.*; ;FflEL<7Y
,#OG/r-H
=:8=5tj
public class FileAccessI implements Serializable{ OVf|4J/Yx
0j MI)aY.
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CoXL;\
RandomAccessFile oSavedFile; L%Q *\d
long nPos; 08jQq#
1A.\Ao
wGX"R5
public FileAccessI() throws IOException }"H900WE|
{ )pa|uH+N
this("",0); 1*b%C"C
} @?? 6)C
O G}&%NgH
tTp`e0L*m
public FileAccessI(String sName,long nPos) throws IOException XhV"<&v
{ Y2&6xTh
oSavedFile = new RandomAccessFile(sName,"rw"); V@-GQP1
this.nPos = nPos; U5 "v1"Ec
oSavedFile.seek(nPos); s>I}-=.(Q
} =ab}.dWC
qrh7\`,.m/
f+AIxSw
public synchronized int write(byte[] b,int nStart,int nLen) h(sKGCG
{ i.4[]f[/h
int n = -1; R~-q!nC
try{ =@l5He.]&
oSavedFile.write(b,nStart,nLen); J<@]7)|U
n = nLen; ['1?'*
} *E_= 8OV
catch(IOException e) f|5|n>*
{ R.;59s
e.printStackTrace (); ,CF~UX% bU
} ^KR(p!%
p?nVPTh
u\?u}t v
return n; 75i)$}_1B
} wX;NU4)n
P'k39
ond/e&1
} iJeT+}
}clNXtN
5]+eLKXB
/* &>{L"{
**SiteInfoBean.java | 'G$}]H
*/ v}@6"\
package NetFox; 2&#iHv
30"G%DFd
o\[nGf C&
public class SiteInfoBean { `#F>?g$2
uESHTX/[
n1h+`nsf
private String sSiteURL; //Site's URL rD?o97
private String sFilePath; //Saved File's Path ]A[~2]
private String sFileName; //Saved File's Name C?k4<B7V
private int nSplitter; //Count of Splited Downloading File m^KkS
ppA8c6
G>"[nXmcu
public SiteInfoBean() <o}t-Bgg
{//nSplitter的缺省值为5 *L_wRhhk
//default value of nSplitter is 5 '#?hm-Ga
this("","","",5); p9J(,}
} l[Oxf|
X3vrD{uNU
`h#JDcT;a
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .~']gih#
{ 2e&Zs%u
sSiteURL= sURL; nor`w,2VF
sFilePath = sPath; GEgf_C!%@
sFileName = sName; yMxS'j1
this.nSplitter = nSpiltter; i8F~$6C
1'U-n{fD
:+n7oOV
} .w&Z=YM
?##GY;#
oT w1w
public String getSSiteURL() O"GzeEY7
{ ZN^Q!v
return sSiteURL; EBm\rM8
} xgVt0=q
i7_BnJJX{B
N]~q@x;<)3
public void setSSiteURL(String value) fpUX @b
{ "]% L{aP
sSiteURL = value; 89l}6p/L
} ^z1WPI
APya&TG
-xXM/3g1u
public String getSFilePath() h2y@xnn
{ UHHe~L
return sFilePath; JdnZY.{S0
} 3[$VW+YV
EP @=i
a<Ta*:R$0
public void setSFilePath(String value) @<+(40`*
{ 'tc$#f^:
sFilePath = value; $xqphhBg
} F-t-d1w6
~ lS3+H
M II]sF
public String getSFileName() 7)YU ;
{ ;a|A1DmZ
return sFileName; -95`.o
} 3e"G.0vJ
f7L|Jc
Xc.~6nYp
public void setSFileName(String value) ^,50]uX_
{ @/~41\=e
sFileName = value; Q"\[ICu!,
} ,}<v:!
/#HY-b
!&X}?NK
public int getNSplitter() L/shF}<
{ +] uY
return nSplitter; a)xN(xp##
} ,PnEDQ|l
l\bBc,%jt
8d]= +n!
public void setNSplitter(int nCount) SU:Cm:$
{ }'3V(;9
nSplitter = nCount; WZZD
} 2>mDT
} eL],\\q
xH0Bk<`V:
TE/2}XG)
/* IV\@GM:ait
**Utility.java s)>]'ii
*/ }b44^iL$9y
package NetFox; tNtP+v-{
X|b~,X%N
FT=w`NE,+
public class Utility { StE4n0V
UJQ!~g.y]
n1v%S"^
public Utility() ,}bC
{ 45#`R%3
4&?%"2
?qdG)jo=
} ]wP)!UZ
7eY*Y"GX
//线程睡眠 >_R5Li
public static void sleep(int nSecond) h><;TAp
{ '&\km~&
try{ -.xs=NwB.|
Thread.sleep(nSecond); Lz4iLLP
} R+5x:mpHy
catch(Exception e) ]3%Z
{ =U?"#
e.printStackTrace (); K,J:i^2
} ~;{)S}U@R
} \wMr[_LW
H>VuUH|
//日志 >2_J(vm>
public static void log(String sMsg) TkK- r(=
{ M6?*\9E
System.err.println(sMsg); !X8:#a(
} a7ZPV1k
kfn5y#6NZ
k;"=y)@o
public static void log(int sMsg) h:l\kr|9
{ >RRb8=[J
System.err.println(sMsg); B4I|"5G2y
} J)66\h=
} ?QZ\KY
Lt_7pb%
T*z >A
/* 2@=JIMtc
**TestMethod.java a(bgPkPP
*/ "=HCP,
package NetFox; :H6Ipa
<V9L AWeS
9Y~A2C
public class TestMethod { <s $~h
d!8`}L:=M
]XU?Wg
public TestMethod() +DksWbD
{ ///xx/weblogic60b2_win.exe z!eY=G'
try{ faThXq8B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); gVk_<;s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); + 6O5hZ
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'a*tee ^RS
fileFetch.start(); &c0U\G|j
} ZY=x$($f
catch(Exception e){e.printStackTrace ();} UT+B*?,h
/9;)zI
(@mvNlc:
} kE=}.
wS#.Wzp.w
On#RYy^}
public static void main(String[] args) N^B YNqr
{ na_Y<R`
new TestMethod(); }h>QkV,{2
} pGh2 4E
} /wVrr%SN
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