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)); 2u0C~s
} _=ani9E]uF
for(int i=0;i<nEndPos.length-1;i++) >^vyp!
{ 7v9l+OX,6
nEndPos = nStartPos[i+1]; QH:PClW![
} u(W%snl
nEndPos[nEndPos.length-1] = nFileLength; Q2wEt >0a
} [se J'Io
} VFUuG3p)
N 2|?I(\B
*`]LbS
//启动子线程 EjZ_|Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bDh,r!I
for(int i=0;i<nStartPos.length;i++) :q6j{C(
{ :Osw4u]JXd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), EyJWi<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FbxrBM
nStartPos,nEndPos,i); 3f;W+^NY
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Jb. V4
fileSplitterFetch.start(); .L;M-`^
} y#%*aV}|B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j<+QGd%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &DnX6%2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RLuA^ONI
nEndPos = " + nFileLength); X%iiz
// fileSplitterFetch[nPos.length-1].start(); ,Jqi J?,4C
n)]]g3y2
<PCa37
//等待子线程结束 {FV_APL9_
//int count = 0; Ja$Ple*XU8
//是否结束while循环 &j4 1<A
boolean breakWhile = false; crx8+
5X2&hG*
5[^pU$Y
while(!bStop) AcF6p)@_
{ P+tnXT>nE
write_nPos(); 1A>>#M=A
Utility.sleep(500); Y", :u@R
breakWhile = true; E+>$@STv#
;MD6iBD
GEJEhwO;H
for(int i=0;i<nStartPos.length;i++) 5i 56J1EC
{ QFn .<@
if(!fileSplitterFetch.bDownOver) R$vo
{ @m*^v\q<u
breakWhile = false; J!l/!Z>!cF
break; DEmU},<S
} <B,z)c
} p[kEFE,%
if(breakWhile) aZK%?c
break; ko-:)z
$w,&h:.p
85$W\d
//count++; wWaO"N]
//if(count>4) (_2;}eg
// siteStop(); $+#Lq.3,
} )`u)#@x
u 3&9R)J1
3vs;ZBM
System.err.println("文件下载结束！"); zq(R!a6
} 'q+CL&D
catch(Exception e){e.printStackTrace ();} 9NX/OctFa'
} |VlQ0{
nYfZ[Q>v
i+`N0!8lY
//获得文件长度 Knd2s~S
public long getFileSize() La$*)qD,
{ -Xm/sq(i)%
int nFileLength = -1; Iu<RwB[#Q
try{ 58T<~u7
URL url = new URL(siteInfoBean.getSSiteURL()); MiB"CcU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u$A*Vsmr
httpConnection.setRequestProperty("User-Agent","NetFox"); |&O7F;/_
z: x|;Ps!
-Re4G78%
int responseCode=httpConnection.getResponseCode(); s@Q, wa(
if(responseCode>=400) _FG?zE
{ !1g2'
processErrorCode(responseCode); <,r(^Ntz
return -2; //-2 represent access is error G}MJWf Hl
} l$j/Ye]
f$\gm+&hXE
qXI>x6?*
String sHeader; JqX+vRY;dd
RtE2%d$JT
=D1%-ym
for(int i=1;;i++) Hchh2
{ KW17CJ@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U_1syaY!
//Utility.log(in.readLine()); #q[k"x=c
sHeader=httpConnection.getHeaderFieldKey(i); *^]lFuX\&E
if(sHeader!=null) :fxG]uf-P
{ U9uy(KOW
if(sHeader.equals("Content-Length")) ups]k?4
{ 2aROY2
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4T]n64Yid
break; VeLuL:4I
} 6jdNQC$#B
} 6xFvu7L_c;
else ?8{x/y:
break; :E$<!q
} X`REhvT
} F_Pv\?35z
catch(IOException e){e.printStackTrace ();} 82mKI+9&"
catch(Exception e){e.printStackTrace ();} //[zUn
Iuh1tcc
_trF/U<
Utility.log(nFileLength); X>0$zE@0
2swHJ.d\
dZSv=UY)
return nFileLength; Rn"Raq7Cn*
} s]D&):
-!p +^wC
W,\LdQ
//保存下载信息（文件指针位置） g~>g])
private void write_nPos() DU@ZLk3
{ %Ls5:Z=
try{ L?WF[nFR
output = new DataOutputStream(new FileOutputStream(tmpFile)); G;^},%<
output.writeInt(nStartPos.length); {$dq7m(
for(int i=0;i<nStartPos.length;i++) tEj-c@`"x-
{ Oa8lrP`(
// output.writeLong(nPos); >?pWbL
output.writeLong(fileSplitterFetch.nStartPos); BqF%2{
output.writeLong(fileSplitterFetch.nEndPos); 5x([fG
} F4Jc7k2
output.close(); x4r=ENO)q
} V3^=Mj2"
catch(IOException e){e.printStackTrace ();} R]s\s[B
catch(Exception e){e.printStackTrace ();} E{Gkq:
} A,P_|
dZMOgZ.!yr
fR:BF47
//读取保存的下载信息（文件指针位置） _ct18nh9
private void read_nPos() oNkASAd
{ V>8)1)dF
try{ "kYzgi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 1;e"3x"
int nCount = input.readInt(); CG`s@5y>5
nStartPos = new long[nCount]; __F?iRrCM
nEndPos = new long[nCount]; eU[f6OGqC
for(int i=0;i<nStartPos.length;i++) f{} zqCK
{ @Lp;p$G`
nStartPos = input.readLong(); ?0ezr[`.
nEndPos = input.readLong(); Aqc Cb[1r
} |^uU&O;.
input.close(); lur$?_gt
} m'L7K K-Y)
catch(IOException e){e.printStackTrace ();} 'aq9]D_k
catch(Exception e){e.printStackTrace ();} Z~JX@s0v
} 3)?v
*{ =5AW}o
2 /rDi
private void processErrorCode(int nErrorCode) $p(,Qz(.8
{ FuA8vTV{
System.err.println("Error Code : " + nErrorCode); y([""z3<w
} %Ydzzr3
M[;N6EJH
Qh3V[br
//停止文件下载 QG|KZ8uO
public void siteStop() vf|lF9@U
{ igoUKDNiQ-
bStop = true; 0<,Q7onDD:
for(int i=0;i<nStartPos.length;i++) +IRr&J*P
fileSplitterFetch.splitterStop(); pPC_ub
0:,8Ce
X2Z E9b
} yq?7!X
} R%(ww
//负责部分文件的抓取 Hy?+p{{G
**FileSplitterFetch.java tt|v opz
*/ $. ;j4%%
package NetFox; c`hj^t
YTQom!O
)Mtw9[
import java.io.*; UL46%MFQ\
import java.net.*; 0+i\j`O&
&WqKsH$
Q%seV<!/
public class FileSplitterFetch extends Thread { nJdO~0}3
gypE~@
TAkM-iyH]
String sURL; //File URL sRM3G]nUr
long nStartPos; //File Snippet Start Position ?|&plf|
long nEndPos; //File Snippet End Position \Y EV 5
int nThreadID; //Thread's ID \z/_vzz4
boolean bDownOver = false; //Downing is over 34@f(^d+^
boolean bStop = false; //Stop identical bZ/4O*B
FileAccessI fileAccessI = null; //File Access interface Cb{n4xKW6
,>DaS(
SM<kR1bo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f9Vxtd
{ af:wg]g
this.sURL = sURL; 75O-%9lFF
this.nStartPos = nStart; S.!0~KR:U
this.nEndPos = nEnd; YivWvV
nThreadID = id; K*ZH<@o4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 nDdF(|Qt
} C:]&V*d.v4
!A.Kb74
QO'=O}e
public void run() b),_rr
{ F(-1m A&-
while(nStartPos < nEndPos && !bStop) S`!MoIMsD
{ 4z~%gt74O]
&HPzm6.3
33R_JM{
try{ /,>@+^1
URL url = new URL(sURL); ""j(wUp-W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OMr&f8
httpConnection.setRequestProperty("User-Agent","NetFox"); NwK(<dzG
String sProperty = "bytes="+nStartPos+"-"; Qx_K)
httpConnection.setRequestProperty("RANGE",sProperty); pB3dx#l
Utility.log(sProperty); [n53eC
if S) < t
JD\:bI
InputStream input = httpConnection.getInputStream(); v{R:F
//logResponseHead(httpConnection); jh3LD6|s}
`7;I*|
p'`SYEY@Z
byte[] b = new byte[1024]; JG2)-x;9
int nRead; C ?^si
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :&]THUw
{ . PzlhTL7
nStartPos += fileAccessI.write(b,0,nRead); 2Z ? N
//if(nThreadID == 1) dMA"% R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~}SOd<n)|
} UUxDW3K
..ig jc#UF
N"i'[!H%
Utility.log("Thread " + nThreadID + " is over!"); @ =RH_NB
bDownOver = true; =5JTVF
//nPos = fileAccessI.write (b,0,nRead); Jy,Dcl
} G1Qc\mp
catch(Exception e){e.printStackTrace ();} IZ2c<B5&
} R+c {Pl
} 6j]pJ]F6
ty8\@l
'qosw:P
//打印回应的头信息 G(alM=q
public void logResponseHead(HttpURLConnection con) u-CCUMR
{ a;Nj'M~U
for(int i=1;;i++) HWr")%EhD
{ DhQYjC[
String header=con.getHeaderFieldKey(i); #+1*g4m~B
if(header!=null) ]LvpYRU$P
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [*-DtbEk
Utility.log(header+" : "+con.getHeaderField(header)); ODGOWw0
else \#bk$R@
break; 6 u3$ .Q
} UTatcn
} hM!D6: t
:Fm{U0;"
5"f')MKUV9
public void splitterStop() htn"rY(
{ sA3=x7j%c
bStop = true; ^-CQ9r*
} UMg*Yv%
AZmABl
[:HT=LX3
} ]-o0HY2
GEg8\
ZMSP8(V
/* 0]dL;~0y.
**FileAccess.java Kvu0Av-7
*//文件访问(定位，写) ''9FB5
package NetFox; k1A64?p
import java.io.*; a95QDz
QR!8n
U]!D=+
public class FileAccessI implements Serializable{ t83n`LC
8:j8>K*6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u S$:J:Drx
RandomAccessFile oSavedFile; e1e2Wk
long nPos; wv 7jES
C<!%VHs
V 0<>Xo%
public FileAccessI() throws IOException WJG&`PP
{ L< MIl[z7
this("",0); EwSE;R -
} ( }DCy23
:*wnO;eN
JW!SrM xF
public FileAccessI(String sName,long nPos) throws IOException AiXxn'&i
{ P^-tGo!
oSavedFile = new RandomAccessFile(sName,"rw"); SwESDo)
this.nPos = nPos; 0K-jF5i$`
oSavedFile.seek(nPos); 3P1OyB
} tHhA_
,q yp2Y7
?#F}mOVAa
public synchronized int write(byte[] b,int nStart,int nLen) %N!2 _uk5
{ wo;`D
int n = -1; @u./VK
try{ `I.Uw$,P
oSavedFile.write(b,nStart,nLen); *i[^-
n = nLen; Z8??+d=
} mlgw0
catch(IOException e) ?]S!-6:
{ pKrol]cth8
e.printStackTrace (); o=`FGowF
} W s!N%%g
%J06]FG7
a7#J af
return n; ?)9mHo^
} tA+ c
mZVYgJQ[
/cBQE=]6
} L]o 5=K
?XVJ$nzW
gB!K{ Io'
/* m:77pE&o
**SiteInfoBean.java /? n 9c;w
*/ $=8?@My<
package NetFox; ?`Oh]2n)6
jI$}\*g
(ilU<Ht
public class SiteInfoBean { F`9;s@V*
M2ig iR
i"uAT$xe
private String sSiteURL; //Site's URL !$'s?rnh
private String sFilePath; //Saved File's Path pU`4bT(w%
private String sFileName; //Saved File's Name yQ> *F
private int nSplitter; //Count of Splited Downloading File O>^0}
_zQ3sm
9,|&+G$
public SiteInfoBean() L3M]06y
{//nSplitter的缺省值为5 #NM.g
//default value of nSplitter is 5 #`6A}/@.+
this("","","",5); bdiyS.a-
} NJb5HoYZ
`jR;RczC
N{@kgc
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) YX+Da"\
{ /8baJ+D"4\
sSiteURL= sURL; S8+Xk= x
sFilePath = sPath; CCJ!;d;&87
sFileName = sName; /#?lG`'1
this.nSplitter = nSpiltter; QKYGeT7&Y'
9k_3=KS3N
tk5Bb`a
} h5Y3 v
FAAqdK0
6Cut[*lj^
public String getSSiteURL() I(r^q"
{ [o)P
return sSiteURL; J;Az0[qMR
} #2c-@),
5-|fp(Ww_W
Qci<cVgP
public void setSSiteURL(String value) FJ3Xeos4|
{ $l:?(&u
sSiteURL = value; |y@TI
} &$fe%1#
F"9f6<ge
)J+vmY~&
public String getSFilePath() 7\aLK#
{ 9viQ<}K<
return sFilePath; r=dFk?8XbC
} S86%o,Saq\
VIL #q
Ml8'=KN_
public void setSFilePath(String value) ANh5-8y
{ >\b=bT@iM
sFilePath = value; 2s,wC!',
} >S5:zz\
,L&Ka|N0
)+[IR
public String getSFileName() |MvCEp
{ xz YvD{>
return sFileName; JpDc3^B*
} @*W,Jm3Y
`zAo IQ
j3F[C:-zY
public void setSFileName(String value) ]*-9zo0
{ -\yaP8V
sFileName = value; [Dp6q~RM
} eHG**@"X
a 1bu
J?$4Yf
public int getNSplitter() _T^ip.o
{ LRD71*/
return nSplitter; ( B$;'U<
} XiI@Px?FL
0q"&AxNsP
uj_uj!
public void setNSplitter(int nCount) r?d601(fa
{ d;\x 'h2
nSplitter = nCount; $(_Xt-6
} BuI&kU,WY
} rWF~aec
>L?)f3_a
*""'v
/* uY5&93R
**Utility.java FLY#
*/ .Vq-<c%
package NetFox; XXacWdh \
#X7fs5$&
&ZFsK c#
public class Utility { n@w$5y1@
=kohQ d.n
xtN%v0ZZ
public Utility() 0Ep%&>@
{ l"!.aIY"e
?f[#O&#
j&)+qTV
} [-_u{j
m6QlIdl
//线程睡眠 yL&F!+(/Ix
public static void sleep(int nSecond) ? e%Pvy<i
{ qR!SwG44+
try{ ]1rr$f9
Thread.sleep(nSecond); RUm1;MWs
} Fsv%=E{
catch(Exception e) I(ds]E ;_E
{ Z6SM7?d
e.printStackTrace (); z^S=ji U++
} ;id0|x
} K=VYRY
VWd=7
//日志 r8+{HknB;
public static void log(String sMsg) om$)8'A,l
{ I :%(nKBK
System.err.println(sMsg); L~SM#?z:ue
} HS]|s':
"zR+}
f$9V_j-K+
public static void log(int sMsg) &H;0N"Fn
{ G$:T!
System.err.println(sMsg); ` :Am#"j]}
} Dms6"x2
} W1M<6T.{7
=:mD)oX*
&%L1n?>Q}
/* j*<H18^G
**TestMethod.java v7T05
*/ #rqLuqw
package NetFox; E"&fT!yi
z'3
2Q,e1'=
public class TestMethod { $S|bD$e
B@G'6 ?
bcC;i~9
public TestMethod() `gfh]7T
{ ///xx/weblogic60b2_win.exe #, W7N_mt
try{ mu04TPj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]wWN~G)2lV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0RN]_z$;H
SiteFileFetch fileFetch = new SiteFileFetch(bean); z%(m:/N70
fileFetch.start(); 1XUsr;Wz
} 0sto9n3
catch(Exception e){e.printStackTrace ();} su>GeJiPW
5Q,#Co
w_q{C>-cR
} _n@#Lufx
J7/"8S_#N
c?"#x-<1s
public static void main(String[] args) y|Tb&XPD
{ :w:hqe|_
new TestMethod(); w4<1*u@${
} j8WnXp_
} \I1+J9Gl
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