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)); E4[}lX}
} |$+5@+Zz
for(int i=0;i<nEndPos.length-1;i++) )TmtSSS
{ 3,eIB(
nEndPos = nStartPos[i+1]; ma& To=
} P0GeZ02]
nEndPos[nEndPos.length-1] = nFileLength; ,FQK;BU!lh
} NAr1[{^E,
} _GoVx=t
KL?)akk
Pz"`MB<'Ik
//启动子线程 (pR.Abq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #AViM_u
for(int i=0;i<nStartPos.length;i++) olYsT**'
{ XcfKx@l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M>H=z#C>/A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), my.`k'
nStartPos,nEndPos,i); W WG /k17
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'mMjjG9
fileSplitterFetch.start(); }_OM$nzj
} fI|[Z+"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), f4('gl9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^U q
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d/,E2i{I7
nEndPos = " + nFileLength); \5><3*\
// fileSplitterFetch[nPos.length-1].start(); 8v92Ng7
&tI#T)SSs
k|E]YvnfG
//等待子线程结束 0ZI(/r
//int count = 0; RW7(r/C
//是否结束while循环 7C,T&g 1:
boolean breakWhile = false; IB5BO7J
-X1X)0v$
n!ok?=(kQ
while(!bStop) SZ!=`a]
{ I9y.e++/
write_nPos(); cma*Dc
Utility.sleep(500); 3I=kr
breakWhile = true; XhW %,/<
M8;lLcgu.
W{"XJt_
for(int i=0;i<nStartPos.length;i++) )g1a'G
{ Iw=Sq8
if(!fileSplitterFetch.bDownOver) @,H9zrjVFZ
{ u5E]t9~Pq
breakWhile = false; Rm>^tu -
break; E;(Rm>lB
} &Ral+J
} ^ @=^;nB
if(breakWhile) w!3>N"em
break; /2uQCw&x-
0tz:Wd*<
>yK0iK{
//count++; =tdSq"jh
//if(count>4) m}Y0xV9
// siteStop(); `$5UHa2/
} \FzM4-
15H6:_+=0
:14i?4Fd
System.err.println("文件下载结束！"); L2z2}U=<
} /.Jb0h[W1
catch(Exception e){e.printStackTrace ();} *,WP,-0
} dE=Ue#1U@5
Qo0H
I4_d[O9
//获得文件长度 lX!`zy{3k
public long getFileSize() 6j9)/HP
{ c+' =hR[
int nFileLength = -1; &*,:1=p
try{ H=MCjh&$q
URL url = new URL(siteInfoBean.getSSiteURL()); H#d:kilNy
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i8pU|VpA
httpConnection.setRequestProperty("User-Agent","NetFox"); {U11^w1"3
b\55,La
Jobiq]|>
int responseCode=httpConnection.getResponseCode(); U]4pA#*{|
if(responseCode>=400) v:_B kHN'
{ l:(Rb-Wy
processErrorCode(responseCode); iZ,YxN<R
return -2; //-2 represent access is error *TdnB'Gd
} 4&^9Wklj
j .A6S`
>v5k{Cbp0
String sHeader; 83ipf"]*
N=1JhjVk"
tykB.2f
for(int i=1;;i++) 5i So8*9}
{ (Ye>Cp+]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jx`QB')kX
//Utility.log(in.readLine()); O9h+Q\0\W
sHeader=httpConnection.getHeaderFieldKey(i); gPC@Yy
if(sHeader!=null) W0`Gc {
{ !Jfs?Hy
if(sHeader.equals("Content-Length")) {{yt*7k{
{ E8}+k o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !b|'Vp^U
break; .w? .ib(
} s4= "kT]
} 0Fr1Ku!
else _!V%fw
break; PH4%R]{8{
} ;&;W T
} Ze^jG-SL$9
catch(IOException e){e.printStackTrace ();} 2(YPz|~W
catch(Exception e){e.printStackTrace ();} rw%l*xgX
!$qKb_#nC
i, nD5@#
Utility.log(nFileLength); ]rBM5~
)hKS0`$|
}OShT+xeX
return nFileLength; GJ(d&o8
} CZ{k@z`r
2s ,8R
P* #8ZMA<
//保存下载信息（文件指针位置） +{`yeZ9S
private void write_nPos() w=b(X q+:
{ *<V^2z$y_
try{ 3yS
output = new DataOutputStream(new FileOutputStream(tmpFile)); TW&DFKK`
output.writeInt(nStartPos.length); JN3cg
for(int i=0;i<nStartPos.length;i++) ``Q2P%
{ ^C^*,V3
// output.writeLong(nPos); 'C+;r?1!h
output.writeLong(fileSplitterFetch.nStartPos); *e"a0
output.writeLong(fileSplitterFetch.nEndPos); cd@.zg'sYn
} @]CF&: P A
output.close(); jk~:\8M(A
} Fw4*
catch(IOException e){e.printStackTrace ();} 8Z#j7)G
catch(Exception e){e.printStackTrace ();} sYbH|}
} ?h\mk0[
}k$4/7ri
wOgE|n
//读取保存的下载信息（文件指针位置） S4NL "m
private void read_nPos() eo]#sf@\0
{ e,1u
try{ @)YY\l#
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &R-H"kK?
int nCount = input.readInt(); *=F(KZ
nStartPos = new long[nCount]; B33$ u3d
nEndPos = new long[nCount]; AD5) .}[F
for(int i=0;i<nStartPos.length;i++) WPuz]Ty
{ /)|X.D
nStartPos = input.readLong(); v@ C,RP9
nEndPos = input.readLong(); l3i,K^YL
} ]n1dp2aH
input.close(); 2h~-
} f?fKhu2
catch(IOException e){e.printStackTrace ();} .q`{Dgc~
catch(Exception e){e.printStackTrace ();} #G^A-yjn
} +54aO
Tt# bg1
D@Da0
private void processErrorCode(int nErrorCode) 8pZ<9t'
{ t@zdmy
System.err.println("Error Code : " + nErrorCode); 'w/qcD-
} "`tXA
0Dv JZ|e
Jcf"#u-Q/
//停止文件下载 ~XM[>M\qB
public void siteStop() nn~YK
{ B;zt#H4
bStop = true; TvhJVVQ+?
for(int i=0;i<nStartPos.length;i++) N0TeqOi4Y
fileSplitterFetch.splitterStop(); Ibr%d2yS=
b}z`BRCc
6Y*;{\Rd
} RNJFSD.
} Va<HU:<
//负责部分文件的抓取 jRZ%}KX
**FileSplitterFetch.java 0NE{8O0;Fr
*/ 5a`%)K
package NetFox; |WQ9a' '
6.Ie\5-a;
&]p}+{ (>
import java.io.*; ".2K9j7$
import java.net.*; s'I)A^i+
V-W'RunnW
*dE^-dm#
public class FileSplitterFetch extends Thread { ?H|T&66
Ggm` ~fS
-$8.3\6h
String sURL; //File URL L_O$>c
long nStartPos; //File Snippet Start Position 3fS}:!sQ
long nEndPos; //File Snippet End Position mX# "+X|
int nThreadID; //Thread's ID %|Qw9sbd
boolean bDownOver = false; //Downing is over Y>6.t"?Q^
boolean bStop = false; //Stop identical $n=lsDnhQ
FileAccessI fileAccessI = null; //File Access interface {ShgJ;! Q
mB55PYA
Un=a fX?j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q s(Bnb;
{ sRRI3y@
this.sURL = sURL; 3}Xc71|v
this.nStartPos = nStart; Mhpdaos
this.nEndPos = nEnd; /Bv#) -5
nThreadID = id; y.a]r7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t%0?N<9YkU
} I*)VZW
F4I6P
#;r]/)>
public void run() X)Gp7k1w
{ Ww9;UP'G
while(nStartPos < nEndPos && !bStop) ?m%h`<wgMc
{ %e%7oqR?
_^!vCa7f
o+?@5zw-&
try{ J1F{v)T'?
URL url = new URL(sURL); NP t(MFK\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m2bDHQ+
httpConnection.setRequestProperty("User-Agent","NetFox"); 6qp5Xt+
String sProperty = "bytes="+nStartPos+"-"; I44s(G1jl
httpConnection.setRequestProperty("RANGE",sProperty); wz(K*FP
Utility.log(sProperty); 440FhDMj
p]|LV)R n
*o?i:LE]
InputStream input = httpConnection.getInputStream(); Fz"ff4Bx [
//logResponseHead(httpConnection); pa/9F[
#gZ|T M/h
C3;[e0.1b
byte[] b = new byte[1024]; UZxmhsv
int nRead; GrI&?=S^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ocA]M=3~k
{ wT_^'i*@I
nStartPos += fileAccessI.write(b,0,nRead); f=:.BR{
//if(nThreadID == 1) 5~VosUpe7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fj']?a!m
} ?T'][q
;Rnhe_A.
QApyP CH
Utility.log("Thread " + nThreadID + " is over!"); BSUPS+@+
bDownOver = true; T_hV%
//nPos = fileAccessI.write (b,0,nRead); .XH8YT42
} dk5|@?pe
catch(Exception e){e.printStackTrace ();} Bq}x9C&<
} DZ`k[Z.VZ
} =Viy^ieN$
V|?WF&
Yv\!vW7I
//打印回应的头信息 |r=DBd3
public void logResponseHead(HttpURLConnection con) &"S/Lt
{ ;bjnL>eW
for(int i=1;;i++) NB)t7/Us
{ v|@1(
String header=con.getHeaderFieldKey(i); uH{'gd,q8
if(header!=null) #BJ\{"b_}z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h8v>zNf'
Utility.log(header+" : "+con.getHeaderField(header)); /6tcSg)
else >{&A%b4JF
break; 7`Du5>b8
} rxE&fjW
} ^#SBpLw
h_ ZX/k
rz
public void splitterStop() f1cl';
{ esq<xuZM4
bStop = true; $Z6D:"K
} Bymny>.M
^Q2ZqAf^a
$I8[BYblB
} qei$<j'b
uWc:jP
xs1bxJ_R
/* Q_}n%P:u
**FileAccess.java "$@,n7k
*//文件访问(定位，写) U$J5r+>
package NetFox; -Bv12ymLG
import java.io.*; $9H[3OZPVv
TzF0/T!
pGkef0p@
public class FileAccessI implements Serializable{ a<p %hY3
w%u5<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (j N]OE^
RandomAccessFile oSavedFile; :~-i&KNk
long nPos; [4gjC
AU`OESSI
9[{sEg=C$e
public FileAccessI() throws IOException 3^~Zj95M
{ B9W/bJ6%
this("",0); "::9aYd!
} ~d+O/:=K_
.0 X$rX=
lC{L6&T
public FileAccessI(String sName,long nPos) throws IOException 04\Ta
{ ..$>7y}
oSavedFile = new RandomAccessFile(sName,"rw"); ?*o;o?5s^
this.nPos = nPos; LDX y}hm)
oSavedFile.seek(nPos); ?N_)>&b
} T{HfP
Oga1u
G5umeqYC
public synchronized int write(byte[] b,int nStart,int nLen) n)CH^WHL&
{ 88YC0!Ni
int n = -1; _LsYMUe
try{ L9J;8+ge
oSavedFile.write(b,nStart,nLen); gvr]]}h:O
n = nLen; .+uVgSN
} j4vB`Gr]
catch(IOException e) J/[7d?hI/
{ .b~OMTHuvM
e.printStackTrace (); *h])mqhB
} ?o>6S EGW
k(9s+0qe
24O d]f
return n; JU2P%3
} VO|u8Z"
P2QRvn6v
ir+8:./6
} "i(U
_Q^y_f
GZ,j?@
/* )u Qvt-
**SiteInfoBean.java ChVY Vx(
*/ i6A$1(:h
package NetFox; c}'Xoc
8xgc[#
!xH,y
public class SiteInfoBean { n4R]+&*
b<\GI7
x3_,nl
private String sSiteURL; //Site's URL Ks51:M
private String sFilePath; //Saved File's Path ^T+<!k
private String sFileName; //Saved File's Name 1sMV`qv>
private int nSplitter; //Count of Splited Downloading File !,R
8z0Hx
/t5g"n3
public SiteInfoBean() (E IRz>
{//nSplitter的缺省值为5 Ga?UHw~
//default value of nSplitter is 5 Pgx+\;w"
this("","","",5); 13\Sh
} aYR\<02
9Mnem*
CP@o,v-
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) bsMC#xT
{ |&(H^<+Xp
sSiteURL= sURL; qb9}&'@:
sFilePath = sPath; U#iT<#!l2
sFileName = sName; VrudR#q
this.nSplitter = nSpiltter; E4hq}
XWc|[>iO
nHE+p\
} "LXXs0
dZ-Ny_@&
EO"=\C,
public String getSSiteURL() v(a9#bMZU
{ M$#+W?m&
return sSiteURL; Qk|( EFQ9
} d{?)q
e5FCqNip'
#%qqL
public void setSSiteURL(String value) rdFs?hO
{ pDP33`OFh
sSiteURL = value; <%he o
} rT o%=0P
~;TV74~rr
E8+8{ #f;
public String getSFilePath() vsjM3=
{ =SA 4\/
return sFilePath; Bk@bN~B4
} |%n|[LP'
3SmqXPOw
sek6+#|=
public void setSFilePath(String value) h!ZZ2[
{ ER/\ +Z#Z
sFilePath = value; B>1M$3`E
} 0H;"5
R,uJK)m
oJhEHx[f
public String getSFileName() hcj{%^p
{ {E3;r7
return sFileName; }`#j;H$i
} ='KPT1dW*
bn5"dxV
9tW3!O^_
public void setSFileName(String value) -DA;KWYS
{ K,Lr+
sFileName = value; oC5gME"2
} N45s'rF
OX'/?B((
hU |LFjc
public int getNSplitter() }o~Tw?z-|
{ )kFme=;
return nSplitter; ]eY Qio!
} :Xb*m85y
:/ ~):tM
v\J!yz
public void setNSplitter(int nCount) 9c#L{in
{ D-;J;m \
nSplitter = nCount; AviT+^7E
} u!sSgx=
} M|5^':Y
^w.k^U=B
SZNFE
/* ER0TY,
**Utility.java }Ox2olUX
*/ Z`e$~n(Bh
package NetFox; AEBw#v!,o
*9\oD~2Y
IO?~b XP
public class Utility { ,"4X&>_f
bfcD5:q
fJ,8g/f8
public Utility() *C,$W\6sz
{ 1Al=v
:DF`A(
;Of?fe5:
} 4yJ01s
D7 8)4>X
//线程睡眠 Z?.:5#
public static void sleep(int nSecond) 7N&3FER
{ EuhF$L1
try{ 2n<qAl$t
Thread.sleep(nSecond); !&W"f#_Z
} Yqq$kln
catch(Exception e) QSlf=VK*y
{ :/I={)5
e.printStackTrace (); pP=_@3 D
} M)bC%(xJ
} vq@#Be?@
p]atH<^;K
//日志 1aXIhk4
public static void log(String sMsg) DR#3njjEC
{ P2<gHJ9t
System.err.println(sMsg); ?etj.\q6
} C{lB/F/|!
+9&ulr
IFHgD}kp%#
public static void log(int sMsg) :Map,]]B_
{ *}50q9)/
System.err.println(sMsg); p;)klH@X
} 67EDkknt
} @pyA;>U
74</6T]^
|qFN~!
/* U^WQWa
**TestMethod.java YQlpk@X`2
*/ zXA= se0U
package NetFox; [bQ8A(u
n~L'icD[
[xH2n\7
public class TestMethod { IWSEssP
av$\@4I
#dXZA>b9
public TestMethod() @=^jpSnZ
{ ///xx/weblogic60b2_win.exe vCrWA-q#
try{ vM$#m1L?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Xqq?S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eFeCS{LV+
SiteFileFetch fileFetch = new SiteFileFetch(bean); 'JXN*YO
fileFetch.start(); ?j ;,q
} OmQuAG ^\x
catch(Exception e){e.printStackTrace ();} oD|+X/FK
B@:XC&R^
`jl. f
} y[Fw>g1`q
$ET/0v"V
<{P^W;N7
public static void main(String[] args) Wl^/=I4p#
{ n,R[O_9u[
new TestMethod(); l"V8n BR`
} &vGEz*F
} o7Z#,>`2
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