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)); 6<FJ`l]U9
} E9QNx62
for(int i=0;i<nEndPos.length-1;i++) ,odjL6u
{ aZ#c_Q#gZ
nEndPos = nStartPos[i+1]; 2i8'*L+j
} B +_D*a
nEndPos[nEndPos.length-1] = nFileLength; u]CW5snz
} SC"=M^E
} [R6du*P
i7:j(W^I8
Pqx=j_st
//启动子线程 8%I4jL<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *(s)CWf
for(int i=0;i<nStartPos.length;i++) Wv$e/N`l
{ 5zfPh`U>1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ExV>s*y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GiI2nHZc
nStartPos,nEndPos,i); c7'I'~
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q48V|6X'q
fileSplitterFetch.start(); z&9vKF
} w9l)=[s=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;%hlh)k$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :E]A51
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X2T)]`@
nEndPos = " + nFileLength); 5>"-lB &
// fileSplitterFetch[nPos.length-1].start(); f`P%aX'cBQ
DYbkw4Z,
3>/Yku)t
//等待子线程结束 ?ZE1>L7e
//int count = 0; 8x[q[
//是否结束while循环 (H0nO7Bk
boolean breakWhile = false; (Kv[~W7lb
cqi: Rj
$nBzYRc"3
while(!bStop) M*{EK
{ =)(sN"%
write_nPos(); og!Uq]U/y
Utility.sleep(500); u%3Z +[
breakWhile = true; 315Rk!{AJ
!2$O^ }6"
\} P}H
for(int i=0;i<nStartPos.length;i++) OT\[qaK
{ zT`LPs6T
if(!fileSplitterFetch.bDownOver) l^WFMeMD3a
{ ,B h[jb`y
breakWhile = false; [uW{Ap~2
break; qP*$wKY,
} :1s6h%evrT
} #*1\h=bzmW
if(breakWhile) i{ eDV
break; qGr(MDLc
KKl8tI\u~
>Ix)jSNLgo
//count++; 9^3y\@ m
//if(count>4) 7YkxIzE
// siteStop(); {pm>F}Cwy
} ]7fqVOiOu
rW&8#&
>& \QLo[5
System.err.println("文件下载结束！"); 4Ts5*_
} 83Bp_K2\
catch(Exception e){e.printStackTrace ();} n\ZDI+X
} 9=K=gfZ
#p6#,PZ
5<Xq7|Jt
//获得文件长度 &iId<.SiJ
public long getFileSize() Oy&Myjny<
{ IH'DCY:
int nFileLength = -1; #=q)>+\
try{ "#qyX[\
URL url = new URL(siteInfoBean.getSSiteURL()); 9#@dQ/*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9^c\$"2B
httpConnection.setRequestProperty("User-Agent","NetFox"); ccZ A
%, XyhS5[o
wBA[L}
int responseCode=httpConnection.getResponseCode(); m+s^K{k}
if(responseCode>=400) $ GL$ iA
{ KaZ$!JfT
processErrorCode(responseCode); 3z!\Z[
return -2; //-2 represent access is error 2~K.m@U}!Z
} K9;pX2^z9
Sz.jv#Y
=pF 6
String sHeader; LTm2B_+
.UU BAyjm
'&xv)tno
for(int i=1;;i++) K\`L>B. 1
{ #y~^!fdp9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x$cs_q]J
//Utility.log(in.readLine()); GBGGV#_q'}
sHeader=httpConnection.getHeaderFieldKey(i); ?Xx,[Z&
if(sHeader!=null) (sq4
{ ??CtmH
if(sHeader.equals("Content-Length")) o>';-} E
{ 2$jTj<.K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z1wN+Y.CA
break; oL2|@WNj,
} o=X6PoJN_
} {]n5h#c 5*
else 1t WKH
break; $,bLK|<hi
} 6OkN(tL&.
} _iO,GT=J-
catch(IOException e){e.printStackTrace ();} =P<gZ-Cm
catch(Exception e){e.printStackTrace ();} Wt"fn&R}
A<C`JN}
:lcZ)6&S
Utility.log(nFileLength); S2HGf~rE
&s>HiL>f
"~jt0pp
return nFileLength; .#2YJ~
} Q *![u5#
\`-/\N
>sv|
//保存下载信息（文件指针位置） y<.0+YL-e+
private void write_nPos() (A}##h
{ HW;,XzP=
try{ ;X[mfg\
output = new DataOutputStream(new FileOutputStream(tmpFile)); [k ZvBd
output.writeInt(nStartPos.length); 6'3@/.
for(int i=0;i<nStartPos.length;i++) w*Vf{[a'
{ uHkL$}C
// output.writeLong(nPos); %K@D{)r_^
output.writeLong(fileSplitterFetch.nStartPos); G9TK)Nz
output.writeLong(fileSplitterFetch.nEndPos); -n?}L#4%8
} hu%UEB
output.close(); RXP0 4
} U N1HBW;
catch(IOException e){e.printStackTrace ();} : |#Iw
catch(Exception e){e.printStackTrace ();} )@DH&
} rDX_$,3L
Z$ {I4a
,^3eMn
//读取保存的下载信息（文件指针位置） {s6;6>-kPW
private void read_nPos() 9[N+x2q
{ lX/6u E_%
try{ J@54B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,3Y~ #{,i
int nCount = input.readInt(); gk>-h,>"
nStartPos = new long[nCount]; 1a;Le8
nEndPos = new long[nCount]; zRbooo{N
for(int i=0;i<nStartPos.length;i++) JV=d!Gi[C
{ L1D{LzlBti
nStartPos = input.readLong(); b*LEoQSl0V
nEndPos = input.readLong(); >:%i,K*AM
} &~ QQZ]q6
input.close(); I2hX;pk,
} "Sz pFw
catch(IOException e){e.printStackTrace ();} ;aExEgTq
catch(Exception e){e.printStackTrace ();} lJP6sk
} 6TvlK*<r=
e;5n.+m
=W"BfG
private void processErrorCode(int nErrorCode) v|C)Q %v
{ m=b~Wf39
System.err.println("Error Code : " + nErrorCode); lG;RfDI-
} X3vTyIsn
uvz}qH@j/Q
eN fo8xUG
//停止文件下载 7d*SZmD
public void siteStop() Ml1yk)3G
{ -g(&5._,ZW
bStop = true; uh*b[`e
for(int i=0;i<nStartPos.length;i++) E}sjl
fileSplitterFetch.splitterStop(); <"Z]S^>$
Adp:O"-H1o
#80DM
} }2:/&H'
} Y O;N9wu3f
//负责部分文件的抓取 Sd'!(M^k3
**FileSplitterFetch.java dtw1Am#Ci
*/ ; {$9Sc $
package NetFox; SUsD)!u_H
s,XKl5'+8e
pV]m6!y&
import java.io.*; 3YVG|Bc~_
import java.net.*; n0q5|ES
r e.chQ6
Nlemb:'eP3
public class FileSplitterFetch extends Thread { 3&.?9
mE^mQ [Dk
?W-J2tgss{
String sURL; //File URL [0U!Y/?6lA
long nStartPos; //File Snippet Start Position ;A7HEx
long nEndPos; //File Snippet End Position Ymkk"y.w
int nThreadID; //Thread's ID 5<\&7P3y
boolean bDownOver = false; //Downing is over Y0fX\6=h
boolean bStop = false; //Stop identical xZZW*d_b
FileAccessI fileAccessI = null; //File Access interface Is&z~Xy/
ESp)%
~n9BN'@x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L!s/0kBg
{ <ek_n;R
this.sURL = sURL; *jM~VTXwt
this.nStartPos = nStart; aRPgo0,W1
this.nEndPos = nEnd; yb*P&si5bY
nThreadID = id; ]`)50\pdw
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Mk9'
} pt.0%3
8gwJ%"-K
5 fY\0
public void run() ,6:ya8vB
{ n=!]!'h\:
while(nStartPos < nEndPos && !bStop) $o"Szy
{ V1 T?T9m
1^ZQXUzl%i
(oO*|\9u
try{ ImO\X`{
URL url = new URL(sURL); 3on]#/"1b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )X2=x^u*U
httpConnection.setRequestProperty("User-Agent","NetFox"); u~FXO[b
String sProperty = "bytes="+nStartPos+"-"; rt)70=
httpConnection.setRequestProperty("RANGE",sProperty); &^$dHr6v
Utility.log(sProperty); fr kDf-P
t<s:ut)Q!
zBD ?O!
InputStream input = httpConnection.getInputStream(); N)|mA)S)
//logResponseHead(httpConnection); L1ZhH3}X
n*~=O'
W<C \g~\
byte[] b = new byte[1024]; ,DsqKXSU
int nRead; rKEi1b
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) D{g6M>,\
{ +ptVAg+
nStartPos += fileAccessI.write(b,0,nRead); k?ubr)[)
//if(nThreadID == 1) U/'"w v1y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x LR 2H>B}
} Ex2TV7I
<+@?V$&
Qz/o-W;
Utility.log("Thread " + nThreadID + " is over!"); ZlD\)6 dZ
bDownOver = true; C%#=@HC
//nPos = fileAccessI.write (b,0,nRead); 'lNy&
} ; mnV)8:F
catch(Exception e){e.printStackTrace ();} ^Uss?)jN4
} 17g\XC@ Cl
} S^0Po%d
rUvjc4O}
_1jd{?kt
//打印回应的头信息 Z]f_?@0
public void logResponseHead(HttpURLConnection con) P @N7g`u3}
{ >MD['=J[d
for(int i=1;;i++) 6U[`CGL66
{ t=M:L[bis;
String header=con.getHeaderFieldKey(i); R{Q*"sf
if(header!=null) U5Say3r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R&}"En`$s
Utility.log(header+" : "+con.getHeaderField(header)); ]G.ttfC
else :ad
break; |hms'n0
} Ks 8
} G?D7R/0)
l",JN.w
*6D0>F
public void splitterStop() _aa3;kT_
{ 1|$V
bStop = true; B1dVHz#
} L1=+x^WQ
;Q"xXT`;:
Ay\=&4dv
} *ue- x!"c
/Y$UJt
eF+:w:\h
/* g-`HKoKe
**FileAccess.java bH4'j/3
*//文件访问(定位，写) hu}`,2
package NetFox; V5w00s5?%
import java.io.*; G"w ?{W@
0kxo
K=,nX7Z5
public class FileAccessI implements Serializable{ )p*I(y
VN!`@Ci/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xCU^4DO3p
RandomAccessFile oSavedFile; q =sEtH=
long nPos; ":s1}A
K;,zE6WD$$
lbM)U
public FileAccessI() throws IOException A[lbBR
{ d%1Tv1={
this("",0); p!qV!:
} Ip#BR!$n
xs+pCK|
0/{$5gy&
public FileAccessI(String sName,long nPos) throws IOException `K -j
{ AX6z4G
oSavedFile = new RandomAccessFile(sName,"rw"); HKu? J
this.nPos = nPos; fZ8%Z
oSavedFile.seek(nPos); x'IVP[xh`A
} 8m%+O#
)I7~<$w
4C@ .X[r
public synchronized int write(byte[] b,int nStart,int nLen) wdS4iQD
{ b=nQi./f
int n = -1; =`RogjbP
try{ #[ZF'9x
oSavedFile.write(b,nStart,nLen); Ik[aiz
n = nLen; Ay?KE{Qs '
} B \?We\y
catch(IOException e) &o{=
{ ~*:{U
e.printStackTrace (); nnr g^F
} `/]Th&(5
#p'Xq }]
+ob<? T
return n; 9 0PF)U
} tQ!p<Q= $)
ee7#PE]}
|'@c ~yc
} `PML4P[
}dnO7K
I+nKaN+8i
/* kU uDA><1
**SiteInfoBean.java +/!kL0[v
*/ +; /]'
package NetFox; \:>GF-Z(
VVY#g%(K
qg521o$*
public class SiteInfoBean { $ = uz
yGGQ;!/
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private String sSiteURL; //Site's URL {+D 6o
private String sFilePath; //Saved File's Path E?$|`<o{|`
private String sFileName; //Saved File's Name %:61@<
private int nSplitter; //Count of Splited Downloading File tE&@U$0>o
""AP-7
BS-nny
public SiteInfoBean() w[`2t{^j
{//nSplitter的缺省值为5 Po+I!TL'
//default value of nSplitter is 5 y3!r;>2k=
this("","","",5); Fk&W*<}/;
} 5Q_T=TL
QGv$~A[h
D,cGW,2Nv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Kob i!
{ Af*e:}}
sSiteURL= sURL; rByC6HV"
sFilePath = sPath; -e#~CE-
sFileName = sName; pwj?
this.nSplitter = nSpiltter; w5j6RQml
*g0}pD;r
Y&vn`#
} $U3|.4
P''5A6#5
Cs2hi,s
public String getSSiteURL() .MoOjx?
{ \*>r[6]*&5
return sSiteURL; ~3]ZN'b\
} 93Z/|7
&b!L$@6
!m7`E
public void setSSiteURL(String value) ].E89_|O
{ P'EPP*)q
sSiteURL = value; N?Wx-pK
} X<pg^Y0
>[,ywRJ#_}
h6Femis
public String getSFilePath() /(/Z~J[
{ d!BQ%a
return sFilePath; C!]R0L*
} KyQO>g{R
JnC$}amr
{2|[7oNT6
public void setSFilePath(String value) z]/;?
{ "6[a%f#Q
sFilePath = value; {zTo[i
} B8XW+U
A`|Z2
ld RV JVZc
public String getSFileName() J[Ckz]
{ <>gX'te
return sFileName; TH;kJ{[}
} ny(`An
;$`5L"I5$
'7lHWqN<
public void setSFileName(String value) 4*j6~
{ |@84l
sFileName = value; l|, Hj
} o'oA.'ul
(8Q0?SZN
% oPt],>
public int getNSplitter() {P'_s]B)
{ 5y 9(<}z
return nSplitter; @W4tnM,#
} VR8 kY&
HDmjt+3&n
SJseP_-
public void setNSplitter(int nCount) GJu[af
{ <7U\@si4
nSplitter = nCount; LB(I^
} \&{a/e2:S
} M2pe*z
>9WJa5{
SG5GJCkc
/* [`F}<L."
**Utility.java 4AIo,{(
*/ 5%qq#;[n
package NetFox; X.q,
9.:]eL
&dH[lB
public class Utility { 5Kadh2nz
Aof)WKo
R6(sWN-
public Utility() \ F\ /<
{ e_<'zH_1
QLs9W&PG
0XcH
} $ \yZ;Z:
p)u?x)w=
//线程睡眠 Po)!vL"
public static void sleep(int nSecond) j&(Yk"j+
{ Ipp#{'Do
try{ $dxk;V
Thread.sleep(nSecond); |41NRGgY
} $wr B5m?
catch(Exception e) KQf=t0Z=Ce
{ m{ wk0
e.printStackTrace (); D]?eRO9'
} f3>L/9[[<P
} y;\m1o2
65HP9`5Tm
//日志 Z!/!4(Fh
public static void log(String sMsg) Q!91uNL
{ v)f;dq^z-
System.err.println(sMsg); <:n!qQS6
} ]+"25V'L
3}7`?$5
!J6;F}Pd/
public static void log(int sMsg) '%H\k5^
{ zu,F 0;De
System.err.println(sMsg); <M y+!3\A
} ?rJe"TOIy
} y6hb-: #1
qxQuXF>:#
<Jf[N=
/* I[l8@!0
**TestMethod.java f}!Eu
*/ X([8TR
package NetFox; t'e\Z2
[ ,&O
Irc(5rD7
public class TestMethod { ~pC\"LU`
8v ZY+Q >
; u@& [
public TestMethod() t@;r~Sb
{ ///xx/weblogic60b2_win.exe vG{lxPIj
try{ d:L|BkQ7*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6CV9ewr
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R<)^--n
SiteFileFetch fileFetch = new SiteFileFetch(bean); .eHOG]H
fileFetch.start(); :~{Nf-y0`1
} Q,m&XpZ
catch(Exception e){e.printStackTrace ();} J#*%r)
<2V:tj)?P
MQY}}a-oug
} P3k@ptc-K
2.2G79U,
u)4eu,MBT
public static void main(String[] args) \-W|)H
{ Q1'4xWu
new TestMethod(); W^k|*Y|
} 4G_At
} 3FgTM(
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