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)); Pg8.RvmQ
} 4;AF\De
for(int i=0;i<nEndPos.length-1;i++) $bG*f*w
{ Br!;Ac&N
nEndPos = nStartPos[i+1]; HS<Jp44
} )Jjp^U3Ub
nEndPos[nEndPos.length-1] = nFileLength; ?SNacN@r
} 8H4NNj Oy
} _[R(9KyF0f
jkL=JAcf~
bJIYe ld
//启动子线程 q5_zsUR=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :XhF:c[.:
for(int i=0;i<nStartPos.length;i++) Es+I]o0K
{ (?Mn_FNE|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1L*[!QT4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), b WNa6x
nStartPos,nEndPos,i); )YAa7\Od
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vcFR Td
fileSplitterFetch.start(); 'd~(=6J
} VZt%cq
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e8<}{N0,n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CK[8y&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1gV?}'jq
nEndPos = " + nFileLength); 3*<@PXpK&
// fileSplitterFetch[nPos.length-1].start(); \1Y|$:T/
kf'(u..G
ESB^"|9
//等待子线程结束 &)OI!^ (
//int count = 0; Zye04&x9k
//是否结束while循环 "Ol:ni1
boolean breakWhile = false; zwV!6xG
\ UrD%;sq
08xo_Oysq
while(!bStop) ?XY'<]o E
{ HDV-qYD|O~
write_nPos(); R5ra*!|L)
Utility.sleep(500); 7<)H?;~;
breakWhile = true; z0rYzn?MR
cjN)3L{
F\r"Y)|b=
for(int i=0;i<nStartPos.length;i++) "d)YqQ
{ #ELeW3 S}
if(!fileSplitterFetch.bDownOver) b\0>uU
{ B2kZ_4rB
breakWhile = false; fx|d"VF[
break; t}k:wzZ@
} b@CjnAZ
} f,yl'2{
if(breakWhile) dE"_gwtX
break; uaO.7QSwN
"Vq= Ph
J>v[5FX+
//count++; Md~SzrU
//if(count>4) Z|C,HF+m.
// siteStop(); )>1}I_1j)
} +UDt2
{`D]%eRO
~Y`ys[Z m
System.err.println("文件下载结束！"); Ibz9juY
} yo[Sh6r/9b
catch(Exception e){e.printStackTrace ();} |^-D&C(Eu
} 7nT|yL?
`+n0a@BVB
&j:e<{@
//获得文件长度 :O413#8
public long getFileSize() Pp }Z"
{ 9;LjM ~Ct
int nFileLength = -1; 4wSZ'RTSR
try{ |aLK_]!
URL url = new URL(siteInfoBean.getSSiteURL()); ~+1mH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nx%As
httpConnection.setRequestProperty("User-Agent","NetFox"); bdWdvd:
%JBLp xnq
(Huvo9
int responseCode=httpConnection.getResponseCode(); ~u$cX1M
if(responseCode>=400) \'Ca1[y@B
{ b|-)p+ba
processErrorCode(responseCode); kS_#8I
return -2; //-2 represent access is error 68P'<|u?
} ,+df=>$W
Z$J-4KN
FQ0&{ulb
String sHeader; s/hgWW$
*KNfPh#wi}
u)Kiwa
for(int i=1;;i++) }kt%dDU
{ i&H^xgm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jfK&CA
//Utility.log(in.readLine()); C5^WJx[
sHeader=httpConnection.getHeaderFieldKey(i); eW 4[2Q
if(sHeader!=null) iA{q$>{8
{ WD\Yx~o
if(sHeader.equals("Content-Length")) ]*=!lfrV
{ p^ (Z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); G~y:ZEnN[
break; Rw `ezC#
} /TsXm-g#
} itNuY<"
else gw"SKp!]
break; IT:WiMDQ}
} 1|8Bv0-b
} +pgHCzwJE
catch(IOException e){e.printStackTrace ();} \xp0n
catch(Exception e){e.printStackTrace ();} Y7+c/co
;+C$EJw-
:ILpf+`yY
Utility.log(nFileLength); %J-:%i
&Ih}"
@+t|Aa^g
return nFileLength; W*s=No3C
} 517"x@6Q
nGWy4rY2S
Vaf,
//保存下载信息（文件指针位置） oJNQdW[
private void write_nPos() e46`"}r
{ Y[)mHs2
try{ 00D.Jn
output = new DataOutputStream(new FileOutputStream(tmpFile)); GU`q^q@Ea
output.writeInt(nStartPos.length); 4tUoK[p
for(int i=0;i<nStartPos.length;i++) ;{0alhMZ
{ 3mofp`e
// output.writeLong(nPos); U}:+Hz9
output.writeLong(fileSplitterFetch.nStartPos); 4jDi3MMU9
output.writeLong(fileSplitterFetch.nEndPos); jNx{*2._r
} E4o{Z+C
output.close(); ~D5FnN9
} } *)l
catch(IOException e){e.printStackTrace ();} N`7OJ)l
catch(Exception e){e.printStackTrace ();} esZhX)dS
} _;^x^
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5"40{3
//读取保存的下载信息（文件指针位置） \i[N";K
private void read_nPos() 72RTEGy
{ >0:3CpO*
try{ ea @ H
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w5y.kc;
int nCount = input.readInt(); #tUhul/O
nStartPos = new long[nCount]; NG3:=
nEndPos = new long[nCount]; <(TAA15Xol
for(int i=0;i<nStartPos.length;i++) |FT.x9e-
{ ^m D$#
nStartPos = input.readLong(); Q'cWqr
nEndPos = input.readLong(); D@sMCR
} ueU"v'h\
input.close(); h*KDZ+{)
} 8?m=Vw<kIZ
catch(IOException e){e.printStackTrace ();} (&)uWjq `
catch(Exception e){e.printStackTrace ();} r9(c<E?,h
} SF:{PgGMi
V6ECL6n
fh_:ung
private void processErrorCode(int nErrorCode) ;W+1 H !
{ 9`/ywt3Y
System.err.println("Error Code : " + nErrorCode); c|m?f
} =&-.]|t
gjK: a@{
8KP
//停止文件下载 9\Rk(dd
public void siteStop() ( Ygy%O%
{ OmK0-fa/
bStop = true; >~_>.R+{
for(int i=0;i<nStartPos.length;i++) S=< ]u
fileSplitterFetch.splitterStop(); $hk_v~zM
*WzPxQ_
s#0m
} N/0Q`cQ-
} -"^"& )
//负责部分文件的抓取 ]Zay9jD}c-
**FileSplitterFetch.java <;b
*/ \sVzBHy d
package NetFox; S)2Uoj
>i1wB!gc8
xU.Ymq& 5
import java.io.*; rY6bc\?`x
import java.net.*; Q3)[ *61e
Bt\V1)
jP3~O
public class FileSplitterFetch extends Thread { =>TXo@rVN
6NFLk+kqN
.d)H2X
String sURL; //File URL mp]UUpt
long nStartPos; //File Snippet Start Position <C*%N;F5R
long nEndPos; //File Snippet End Position jI}{0LW&F&
int nThreadID; //Thread's ID QmPHf*w[
boolean bDownOver = false; //Downing is over k|_ >I
boolean bStop = false; //Stop identical ON_GD"
FileAccessI fileAccessI = null; //File Access interface ^dhtc% W>
#0qMYe>Y
9JC8OSjJ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException T:j!a{_|
{ rlDJHR6
this.sURL = sURL; c*>SZ'T\
this.nStartPos = nStart; yF&?gPh&
this.nEndPos = nEnd; g5&,l
nThreadID = id; fAR0GOI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %eqL)pC]
} >\!>CuU
5HbPS%^.
5adB5)`
public void run() x(88Y7o.t
{ o{QPW
while(nStartPos < nEndPos && !bStop) k{$Mlt?&-
{ ] i\a[3
9=^4p=1J
gI~jf- w
try{ *8QGv6*vQ
URL url = new URL(sURL); +4p gPv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B,dKpz;kFg
httpConnection.setRequestProperty("User-Agent","NetFox"); s%qK<U4@;Q
String sProperty = "bytes="+nStartPos+"-"; 5/{gY{
httpConnection.setRequestProperty("RANGE",sProperty); '||),>~
Utility.log(sProperty); IC7S +v
HPR*:t
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InputStream input = httpConnection.getInputStream(); ddD $ 4+
//logResponseHead(httpConnection); !=c&U.B
rRZ ,X%
.@ElfPP(L
byte[] b = new byte[1024]; )TcW.d6
int nRead; rj].bGQ,+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (yel
{ G" Fd]'
nStartPos += fileAccessI.write(b,0,nRead); V<!E9/4rS
//if(nThreadID == 1) xem:#>&r
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \YBY"J
} Gv}h/zu-
=r:-CRq(
;2;Kq)j_=
Utility.log("Thread " + nThreadID + " is over!"); )#dP:
bDownOver = true; b1;80P/:D
//nPos = fileAccessI.write (b,0,nRead); s],+]<qX
} GxGZxf*(
catch(Exception e){e.printStackTrace ();} r`L$[C5I
} RSY{IY
} LPk85E
~WJEH#
%!HmtpS
//打印回应的头信息 q*<Df=+B
public void logResponseHead(HttpURLConnection con) HBL)_c{/O
{ Q[y75 [
for(int i=1;;i++) NTVdSK7z~H
{ ET`;TfqM
String header=con.getHeaderFieldKey(i); !R WX1Z
if(header!=null) zrt8ze=Su
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HzT"{N9
Utility.log(header+" : "+con.getHeaderField(header)); fO.gfHI
else , c/\'k\K)
break; Oav^BhUO
} mMw&{7b:
} (+9_nAgZ,
?/~7\ '|Z
>b0e"eGt
public void splitterStop() 928szUo:
{ b#.hw2?a`
bStop = true; h?DMrYk_%#
} F#Oqa^$(
R)#D{/#FW
#oi4!%*M
} JF_\A)<ki
Sj}@5 X6 C
Z| +/Wl-h
/* V2'(}k
**FileAccess.java >=i47-H
*//文件访问(定位，写) >0SF79-RE
package NetFox; |9!3{3
import java.io.*; HlY4%M5q/
VD.p"F(]
6lq7zi}'w
public class FileAccessI implements Serializable{ ^C@uP9g
VD+8j29
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =[?2'riI
RandomAccessFile oSavedFile; ALwkX"AN
long nPos; 2:/'
%dS7u$Rnh
}jfU qqFd
public FileAccessI() throws IOException L;5jhVy
{ <0R7uH
this("",0); iH( K[F /
} VE6T&fz`
_d]w)YMO
jfS?#;T)
public FileAccessI(String sName,long nPos) throws IOException lVXgp'!#j
{ }`Q'!_`
oSavedFile = new RandomAccessFile(sName,"rw"); <k5FlvE2
this.nPos = nPos; hn.9j"
oSavedFile.seek(nPos); N*lq)@smq
} o]}b#U8S
4G@vO{$
%7O`]ik:
public synchronized int write(byte[] b,int nStart,int nLen) =1^Ru*G
{ -t?S:9[w
int n = -1; <hdR:k@#
try{ g84~d(\?
oSavedFile.write(b,nStart,nLen); NV*aHci
n = nLen; :I F&W=?9
} X&^t 8
catch(IOException e) mh.0% 9`9
{ gUL`)t\}*
e.printStackTrace (); "a5?cX;
} M$%aX,nk'
A]BG*
s3_i5,y
return n; |j^>6nE
} jLD=EJ
F]z xx
05DK-Wh?
} z mrk`o~
A7+eWg{
N~\1yQT
/* zL3~,z/o
**SiteInfoBean.java E} Uy-
*/ WsJ3zZc
package NetFox; ~Rk6@&ZS}
H]UM2.
V{{b^y
public class SiteInfoBean { 'e7<&wm ia
l K}('7\
eO(VSjo'`
private String sSiteURL; //Site's URL G}BO!Z6
private String sFilePath; //Saved File's Path +S^Uw'L$=T
private String sFileName; //Saved File's Name GLnj& Ve
private int nSplitter; //Count of Splited Downloading File -7'>Rw
mZ7.#R*}
Rc0OEs%7P
public SiteInfoBean() `Kpn@Xg
{//nSplitter的缺省值为5 f@[q# }6
//default value of nSplitter is 5 !wJ~p:vRdY
this("","","",5); 9N5&N3
} r$=iM:kERC
{]Nvq9?
$khWu>b
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) z1T.\mzfX
{ (t>BO`,
sSiteURL= sURL; zK k;&y|{
sFilePath = sPath; 1 c3gHc7{t
sFileName = sName; 3"6lPUS
this.nSplitter = nSpiltter; u~bk~3.I
,kpkXK
,m8l /wG
} nP0|nPWz#
n0>#?ek12
s34{\/'D+
public String getSSiteURL() Wf-i)oc4I
{ .,o=#
return sSiteURL; BCJo/m
} :JV=Kt
rs]%`"&=
|XtN\9V.
public void setSSiteURL(String value) g"`BNI]Qp
{ x5.HdKV
sSiteURL = value; brl(7_2
} Xg^`fRg =T
!)?n n3
/[q6"R!uMz
public String getSFilePath() \5_+6
{ M`q>i B
return sFilePath; `J'xVq#O
} g1@zk$
o:.={)rX
COH0aNp;
public void setSFilePath(String value) P6u9Ngay
{ ['~3"lK^O
sFilePath = value; }TzMWdT
} ?T3zA2
({v$!AAv
(+`pEDD{X
public String getSFileName() Q>8F&p?R
{ $A;jl`ng
return sFileName; DJVH}w}9_P
} )a AKO`
5=WzKM
!8lG"l|,l
public void setSFileName(String value) cY8XA6
{ Hbu8gqu
sFileName = value; Bi;D d?.
} Ebw1 %W KC
X; I:i%-
m\o<a|
public int getNSplitter() NRN3*YGo
{ 9>yLSM,!rS
return nSplitter; VT8PV5z
} `Fnl<C<
_0N=~`'
)hs"P%Zg
public void setNSplitter(int nCount) Ir&rTGFN
{ $0$'co"
nSplitter = nCount; ^0)Mc"&{
} yY_(o]k
} R[KF${X4
,5!&}
,I6jfXI4
/* c%y(Z5
**Utility.java ).U\,@[A{
*/ rQmDpoy=
package NetFox; qTSyy=
G"k.sRKu
8Na.H::cZ
public class Utility { "NEg]LB5
4/KGrY!ck
Yc~(Wue
public Utility() [v47_ 5O
{ & -r^Q
#b~B 0:U
h?_Cv*0q
} w O H{L
9mE6Cp.Wv
//线程睡眠 zT<fTFJ1
public static void sleep(int nSecond) grD[7;1~:)
{ "PgVvm#w'
try{ @*?)S{8
Thread.sleep(nSecond); /ILj}g'
} /q|r!+
catch(Exception e) G5WQTMzf&
{ 5(wmy-x\
e.printStackTrace (); 7bV(eV
} 8Z&M}Llk
} Vz.G!*>Dg
Wd`*<+t]
//日志 1`hmD1d
public static void log(String sMsg) FOPfob[
{ [^Z)f<l
System.err.println(sMsg); 5!QT }Um
} In[rxT~K}Q
J#.f%VJ
]ilQq~X
public static void log(int sMsg) ]I,(^Xq3a(
{ A<h^.{
System.err.println(sMsg); jJY{np
} ?F6L,
} ,`Keqfx
p< Y-b,&
c,2OICj
/* eA{nwtN
**TestMethod.java a8WWFAC[
*/ [psZc'q
package NetFox; Pz^C3h$5_
t[e]AU[}
0OXl`V`w
public class TestMethod { Ucx"\/"
+\doF
ZveNe~D7C
public TestMethod() TU6(Q,Yi|
{ ///xx/weblogic60b2_win.exe MY60%
try{ 2tb+3K1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o)bKs>` U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); yV~TfTJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); >\!G43Q=
fileFetch.start(); 3PjX;U|
} 2 \<u;9
catch(Exception e){e.printStackTrace ();} mm9uhlV8
4tEAi4H|`@
Pn,>eD*g
} vX7U|zy
d,b]#fj
)oALB vX
public static void main(String[] args) #bJp)&LO
{ 74 WKy
new TestMethod(); D^QL.Du,
} qSDn0^y
} N%,zME
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