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)); GE=#8-@g~p
} ^I9x@t
for(int i=0;i<nEndPos.length-1;i++) + oyW_!(
{ [vpZ3;
nEndPos = nStartPos[i+1]; @AL,@P/9=
} ^1U2&S
nEndPos[nEndPos.length-1] = nFileLength; dI&2dcumS
} 5I5~GH
} <2w@5qL
BvpGP
ymybj
//启动子线程 !8ub3oj)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =!r9;L,?
for(int i=0;i<nStartPos.length;i++) $@q)IK%FDL
{ 0mL#8\'"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E]6C1C&K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), uYiM~^0
nStartPos,nEndPos,i); 72} MspzUt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [Z0&`qz
fileSplitterFetch.start(); yB(^t`)}N
} ' -[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d;|Pp;dc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $xmltvaF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @jg*L2L6
nEndPos = " + nFileLength); /AWV@'
// fileSplitterFetch[nPos.length-1].start(); =kohQ d.n
xtN%v0ZZ
v]gJ 7x
//等待子线程结束 0Ep%&>@
//int count = 0; l"!.aIY"e
//是否结束while循环 ?f[#O&#
boolean breakWhile = false; j&)+qTV
swuW6p
ro7\}O:I
while(!bStop) R@t?!`f!+
{ UO8#8
write_nPos(); {PGNPxUbe
Utility.sleep(500); e4Ol:V
breakWhile = true; R`Hyg4?
-uN5DJSW
LX4S}QXw
for(int i=0;i<nStartPos.length;i++) & :x_
{ S/]2Qt#T
if(!fileSplitterFetch.bDownOver) [2.uwn]i
{ WcAX/<Y>
breakWhile = false; CD%wi:C%|
break; (4n8[
} ZeF PwW
} #Zk6
if(breakWhile) mYXe0E#6
break; Lllyx20U
FVsVY1
RvvK`}/6
//count++; ~oz8B^7i;
//if(count>4) )Ve?1?s '8
// siteStop(); py9(z`}
} '>_'gR0O
nRN&u4
{,|*99V
System.err.println("文件下载结束！"); c&IIqT@Gb0
} >V@-tT"^:
catch(Exception e){e.printStackTrace ();} XJDp%B
} -?'r_t
u!?.vx<qy
5E?{>1
//获得文件长度 2Q,e1'=
public long getFileSize() M?x/C2|
{ |/[?]`
int nFileLength = -1; jTaEaX8+
try{ 0Jz'9
URL url = new URL(siteInfoBean.getSSiteURL()); ` *x;&.&v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I/rq@27o
httpConnection.setRequestProperty("User-Agent","NetFox"); !.H< dQS
$0V<wsVM
,95Nj h
int responseCode=httpConnection.getResponseCode(); =K~<& l8
if(responseCode>=400) )FGm5-K@
{ Y~hBVz2g
processErrorCode(responseCode); ^tIs57!
return -2; //-2 represent access is error EKhwrBjS
} /`>BPQH`}
_n@#Lufx
J7/"8S_#N
String sHeader; 4a00-y='
;S+*s'e
]re1$W#*
for(int i=1;;i++) a,x-akZWf
{ F]@vmzr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _5EM<Ux
//Utility.log(in.readLine()); w4<1*u@${
sHeader=httpConnection.getHeaderFieldKey(i); b;`gxXeL
if(sHeader!=null) lhva|
{ r ,D T>
if(sHeader.equals("Content-Length")) 2G<\Wz
{ =o;8xKj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <5rp$AzT
break; 6MvjNbQ
} 7RM$%'n\
} lX/s Q
else :^j`wd1 h
break; q+5g+9
} ^.aFns{wv
} K[PH#dF5,x
catch(IOException e){e.printStackTrace ();} UUc{1"z{
catch(Exception e){e.printStackTrace ();} lt`(R*B%
a` A V
QI'ule
Utility.log(nFileLength); t J N;WK.6
!E8y!|7$
v\PqhIy"
return nFileLength; C|bnUN
} x>d,\{U
EE(1;]d-
#S)+eH
//保存下载信息（文件指针位置） WM$}1:O
private void write_nPos() -61{ MMiA
{ ozwPtF5
try{ "MQy>mD6
output = new DataOutputStream(new FileOutputStream(tmpFile)); UUJbF$@;
output.writeInt(nStartPos.length); oP;"`^_
for(int i=0;i<nStartPos.length;i++) / CEnyE/
{ 8+5#FC7
// output.writeLong(nPos); YAQ]2<H
output.writeLong(fileSplitterFetch.nStartPos); yaza
output.writeLong(fileSplitterFetch.nEndPos); P~`gWGC}
} $OB2ZS"
output.close(); 1`J-|eH=Q
} +XCLdf}dC
catch(IOException e){e.printStackTrace ();} ad1I2
catch(Exception e){e.printStackTrace ();} /#lhRNX
} T'B43Q
jI%v[]V
#N9^C@
//读取保存的下载信息（文件指针位置） 8'[g?
private void read_nPos() }5 ^2g!M
{ ZmeSm& hQ_
try{ I ,8
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hAX@|G.
int nCount = input.readInt(); q{~59{Fha
nStartPos = new long[nCount]; kKL'rT6z
nEndPos = new long[nCount]; IA I!a1e!
for(int i=0;i<nStartPos.length;i++) ~(bY-6z
{ U27YH1OK
nStartPos = input.readLong(); KtTv0[66
nEndPos = input.readLong(); &0cfTb)dG
} ?!TFoD2'
input.close(); 9oBK(Sf@^
} HO[W2b
catch(IOException e){e.printStackTrace ();} '[(]62j
catch(Exception e){e.printStackTrace ();} m1H|C3u8
} +9Q,[)e r
3kfrOf.4h
3+vbA;R
private void processErrorCode(int nErrorCode) 2q]y(kW+
{ IlN: NS
System.err.println("Error Code : " + nErrorCode); 0T,uH
} w3l2u1u
m#6RJbEz
)+ifVv50
//停止文件下载 j'r"_*%
public void siteStop() &JMp)zaI[
{ `R[cM;c2
bStop = true; 8LuM eGs
for(int i=0;i<nStartPos.length;i++) >}<1
fileSplitterFetch.splitterStop(); Xb#!1hA
8R|!$P
h;" 9.
} W D8
} j=|cx+nb
//负责部分文件的抓取 p1tqwV
**FileSplitterFetch.java IE*eDj
*/ >D]g:t@v
package NetFox; ]90BIJ]*c
6[+@#IWx
@7S* ]
import java.io.*; qFQO1"mu
import java.net.*; 0b=1Ce+0q
3Ye{a<ckK
_EPfeh;
public class FileSplitterFetch extends Thread { ;::]R'F[
RvQa&r5l
@vyq?H$U;N
String sURL; //File URL #BtJo:
long nStartPos; //File Snippet Start Position ri.}G
long nEndPos; //File Snippet End Position phCItN;
int nThreadID; //Thread's ID V[DiN~H
boolean bDownOver = false; //Downing is over B|WM;Y^
boolean bStop = false; //Stop identical d{/#A%.
FileAccessI fileAccessI = null; //File Access interface !ZxK+Xqx[
}ejZk bP
tKS'#y!R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Lf0X(tC
{ tuK2D,6
this.sURL = sURL; 6LRvl6ik
this.nStartPos = nStart; SG$V%z"e
this.nEndPos = nEnd; {$>Pg/
nThreadID = id; 2WO5Af%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c'|](vOd]
} 5aZbNV}-
N 2XL5<
4og/y0n,l"
public void run() E P3Vz8^
{ b-8}TTL>
while(nStartPos < nEndPos && !bStop) Q DVk7ks
{ r7ebFJEf
uH{oJSrK
%eOO8^N
try{ n2A ; `=
URL url = new URL(sURL); k\76`!B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i(qZ#oN
httpConnection.setRequestProperty("User-Agent","NetFox"); X'uQr+p^
String sProperty = "bytes="+nStartPos+"-"; <aQ<Wy=\
httpConnection.setRequestProperty("RANGE",sProperty); T W#s)iDi
Utility.log(sProperty); `!(IQ&
J?#Xy9dz
MCO2(E-
InputStream input = httpConnection.getInputStream(); ,ZV>"'I:
//logResponseHead(httpConnection); 7Is:hx|:
]9$iUA%Ef
Lv&9s
byte[] b = new byte[1024]; 'fjouO
int nRead; [s{ B vn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !!k^M"e2
{ p>N8g#G
nStartPos += fileAccessI.write(b,0,nRead); %* k`z#b
//if(nThreadID == 1) H\fsyxM7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +'|nsIx,
} Z% DJ{!Hnh
@{>0v"@
!8e;3W
Utility.log("Thread " + nThreadID + " is over!"); -e4TqzRr
bDownOver = true; ~pT1,1
//nPos = fileAccessI.write (b,0,nRead); }el7@Gv
} E1j3c :2
catch(Exception e){e.printStackTrace ();} bWgRGJqt
} 5szJ.!(
} \ )WS^KR%
s*Nb=v.e9
5OCt Q4u
//打印回应的头信息 $b~[>S-Q
public void logResponseHead(HttpURLConnection con) 2@N9Zk{{J
{ ZsNZ3;d@u(
for(int i=1;;i++) ZEK,Z['
{ OO2uE ;( 3
String header=con.getHeaderFieldKey(i); S]&:R)#@
if(header!=null) c)3.AgT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Xub*i^(]
Utility.log(header+" : "+con.getHeaderField(header)); b:5-0uxjs
else jM}(?^@
break; n)0M1o#
} '%X29B5
} 7`j%5%q
%M3L<2
'}^qz#w
public void splitterStop() }Y^o("c(
{ 7gcR/HNeF
bStop = true; = GyABK
} &]h`kvtBC
d6a3\f
YkFAu8b>
} I7wR[&L885
jlA6~n
-2[#1S*
/* eEBo:Rc9
**FileAccess.java ~N%+ZXh&E
*//文件访问(定位，写) r+d+gO.
package NetFox; A`#?Bj
import java.io.*; eBH:_Ls_-^
dF[|9%)
jGi{:}`lB
public class FileAccessI implements Serializable{ 0l3[?YtXc
$4mCtonP=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $q*a}d[Q
RandomAccessFile oSavedFile; 80=LT-%#
long nPos; t`="2$NO
"IB36/9
LZb<-vK"y
public FileAccessI() throws IOException 3%+!qm
{ ;mYZ@g%e
this("",0); ^J&D)&"j
} :C>iV+B j
C1fd@6
b}DC|?~M
public FileAccessI(String sName,long nPos) throws IOException gW<6dP'v
{ otdRz<C
oSavedFile = new RandomAccessFile(sName,"rw"); z4 <_>)p
this.nPos = nPos; Oi'y0S~g
oSavedFile.seek(nPos); R7"7 Rx
} .*f6n|
?em8nZ'
_9]vlxgtG(
public synchronized int write(byte[] b,int nStart,int nLen) -wrVEH8
{ Qd~z<U l
int n = -1; \vJ0Mhk1
try{ ol41%q*
oSavedFile.write(b,nStart,nLen); '}9 Nvr)+
n = nLen; 7H09\g&
} {?Nm"#
catch(IOException e) }`2a>N: &
{ ^.R!sQ
e.printStackTrace (); eKy!Pai
} w\MWr+4
4/%fpU2
t V( WhP
return n; I eJI-lo
} 0@!huk
:._Igjj$=
8h0CG]
} z"T+J?V/
sfipAM
qFK.ULgP`
/* ht*(@MCr<
**SiteInfoBean.java \i/HHP[%
*/ ~&<t++ g
package NetFox; =
IA<>+NS
HHZw-/s,%
public class SiteInfoBean { xVw@pR;
]\KVA)\
^8EW/$k
private String sSiteURL; //Site's URL <$yA*
private String sFilePath; //Saved File's Path `u}_O(A1pA
private String sFileName; //Saved File's Name mZ2CGOR
private int nSplitter; //Count of Splited Downloading File :{N*Z}]
U#cGd\b
&9^4-5]
public SiteInfoBean() .Sn{a}XP4
{//nSplitter的缺省值为5 i%!<6K6UT
//default value of nSplitter is 5 pHoHngyi&
this("","","",5); r-wCAk}m*?
} %'ah,2a%
=y-yHRC7
.SjJG67OyA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &BLCP d
{ J}&U[ds p
sSiteURL= sURL; ,{!,%]bC
sFilePath = sPath; :>.{w$Ln%
sFileName = sName; W03mdRW
this.nSplitter = nSpiltter; 'KIT^k0"Ih
C{}PO u
bJetqF6n
} X5YOxMq
eM_;rMCr}
[:.wCG5
public String getSSiteURL() |,p"<a!+{w
{ WM`3QJb
return sSiteURL; {PX&#,_
} J/'Fj?
gkO^J{_@q
~1D^C |%
public void setSSiteURL(String value) 9c[X[Qc
{ W,NqevXo:
sSiteURL = value; `X5!s
} 2=- .@,6
jhm/<=
wv\K
public String getSFilePath() 3!b $R?kZ
{ $/s"It
return sFilePath; 2L1y4nnbwo
} s[{[pIH
nf^?X`g
S?d<P
public void setSFilePath(String value) CdF;0A9.3
{ =4MTb_
sFilePath = value; ]CF-#q}'
} ppRmC,0f^
g5@JA^\vZT
TL2E|@k1]
public String getSFileName() @>Yd6C
{ R1X'}#mU
return sFileName; sJ|pR=g)!
} >9!J?HA
mFF4qbe
>2znn&gZ
public void setSFileName(String value) ,_u7@Ix
{ I8?
sFileName = value; Q__CW5&'u
} YK)m6zW5
gMI%!Y
wHbkF#[:i
public int getNSplitter() wx*?@f>u^
{ Q"dq_8\`U
return nSplitter; It[51NMal
} c'i5,\#X
gSwV:hm
fgd2jr3T
public void setNSplitter(int nCount) x|a&wC2,{
{ iT :3e%
nSplitter = nCount; Z?{\34lPj
} 6ieul@?*u*
} [*^.$s(
,gVVYH?qR
E`oA(x7l
/* -`I|=lBz{H
**Utility.java Cw+boB_tip
*/ ?YW~7zG
package NetFox; 3W7^,ir
:awkhx
OP1`!P y
public class Utility { ^$:w
QFx3N%
QT,T5Q%JP:
public Utility() d$3rcH1
{ FB[b]+t`D{
LG&BWs!
D6Ad"|Z
} )k=KLQ\b
:')[pO_FW*
//线程睡眠 ]gq)%T]
public static void sleep(int nSecond) Lto*L X
{ &#2&V>pE
try{ fB3Jp~$
Thread.sleep(nSecond); pq{`WgA^
} @!P2f
catch(Exception e) RxMsP;be
{ *)Qv;'U=rn
e.printStackTrace (); Z6zV 9hn
} @3?>[R
} \Osu1]Jn>
WiytHuUF
//日志 PT2;%=f
public static void log(String sMsg) L(TM& ps\-
{ P~trxp=k
System.err.println(sMsg); rw'+2\
} '(5GRI<
GM6,LzH
ELCNf
public static void log(int sMsg) 3%+~"4&
{ G]>yk_#/\U
System.err.println(sMsg); zL yI|%KH
} )$n%4 :
} /A7( `l;6
r!Aj5
~</FF'Xz
/* !1)aie+p6
**TestMethod.java ",b:rgpRp
*/ Dx-P]j)4x
package NetFox; x]c8?H9,&
&'z_:Wm
UTkPA2x
public class TestMethod { LU:xmDv
,R[$S"]!SH
UGPDwgq\v
public TestMethod() Vu5?;|^:
{ ///xx/weblogic60b2_win.exe :oIBJ u%/
try{ %)lp]Y33
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1tNL)x"w
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %Ln`c.C
SiteFileFetch fileFetch = new SiteFileFetch(bean); }Ja-0v)Wf
fileFetch.start(); 4`,(*igEv
} Rml'{S
catch(Exception e){e.printStackTrace ();} (A~7>\r +
0#]fEi
Bg~]u+c*
} z+"$G
dVb6u
OMLU ;,4
public static void main(String[] args) ^>IP"kF
{ gs'M^|e)
new TestMethod(); -%`~3*L
} w jkh*Y
} <<>+z5D+
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