http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); WH :+HNl1d
} L;.6j*E*
for(int i=0;i<nEndPos.length-1;i++) X70vDoW
{ j9C=m"O
nEndPos = nStartPos[i+1]; 5n;|K]UW
} Avw"[~Xd
nEndPos[nEndPos.length-1] = nFileLength; 9[5NnRv$P
} 2YK4SL
} &B3Eq1A
{y0*cC
:K{`0U&l5
//启动子线程 tF)K$!GR[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; bTC2Ya
for(int i=0;i<nStartPos.length;i++) IBl}.o&]B#
{ q|2{W.P5qi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), THQW8 V
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), FM9b0qE
nStartPos,nEndPos,i); M0o=bYI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G1B~?i2$ ?
fileSplitterFetch.start(); pfg"6P
} _J&u{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rPK?pJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GN{\ccej
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )<4o"R:*
nEndPos = " + nFileLength); W"Dj+/uS
// fileSplitterFetch[nPos.length-1].start(); t&SJ!>7_c
d%9I*Qo0,
sAk~`(:4!
//等待子线程结束 '.~vN L+ O
//int count = 0; @FkNT~OZ
//是否结束while循环 &dvJg
boolean breakWhile = false; 5WP[-J)
aGp <%d
.&7=ZY>E
while(!bStop) 4q@o4C<0
{ 3]'=s>UO>^
write_nPos(); ni@D7:h
Utility.sleep(500); v)N6ZOj*C
breakWhile = true; i#lvt#2J0
w;H
wO} 3i6
for(int i=0;i<nStartPos.length;i++) c%pW'UE&
{ CCq<y
if(!fileSplitterFetch.bDownOver) K1O/>dN_\O
{ 9YHSL[
breakWhile = false; <Q\`2{
break; _1y|#o
} 2EE/xnwX
} F)e*w:D
if(breakWhile) "+nURdicO
break; l=9&
!dhZs?/UI
9 K$F.{cx
//count++; *-+~H1tP
//if(count>4) pzU">)
// siteStop(); .j88=t0
} 9ciL<'H\
TOMvJ>bF
g/z9bOgIX
System.err.println("文件下载结束！"); 8f^URN<x
} C==tJog[
catch(Exception e){e.printStackTrace ();} yF0,}
} Z+t?ah00
c'`7p/l.
|nry^zb
//获得文件长度 n4."}DO
public long getFileSize() l$m^{6IYc
{ Bo%M-Gmu
int nFileLength = -1; BqZLqGOKu
try{ 3=bzIU
URL url = new URL(siteInfoBean.getSSiteURL()); ' 1P_*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I4|p;\`fK
httpConnection.setRequestProperty("User-Agent","NetFox"); cIM5;"gLP
vp mSzh
.v1rrH?
int responseCode=httpConnection.getResponseCode(); h:bs/q+-
if(responseCode>=400) WtRy~5A2
{ $<s@S;Ri
processErrorCode(responseCode); 5jNBt>.0
return -2; //-2 represent access is error t1C{
} 1b|<
#s yP=
,7%(Jj$ ^
String sHeader; ;o^m"I\y
G#@<bg3
;k/0N~
for(int i=1;;i++) P\zi:]h[Gh
{ 7KM!\"PM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _IlL'c5
//Utility.log(in.readLine()); (OG@]|-
sHeader=httpConnection.getHeaderFieldKey(i); /-|xxy
if(sHeader!=null) $ @1&G~x
{ `SW`d<+L
if(sHeader.equals("Content-Length")) eHnC^W}|s
{ 82/iVm1
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K=(&iq!VO
break; q6_1`Ew
} #UWQ (+F
} 6@F Z,e
else 3"L$*toRA
break; Be]o2N;J
} GtGToI
} :cC`wX$
catch(IOException e){e.printStackTrace ();} R:ar85F
catch(Exception e){e.printStackTrace ();} 7H>dv'
R2J3R5S=[
0]HK(,/h
Utility.log(nFileLength); n,HWVo>([
,MvvW{EY
&H+<uYV
return nFileLength; g:,4Kd|
} @~N#)L^
"t\9@nzdX
IS=)J( 0
//保存下载信息（文件指针位置） QM_~w\
private void write_nPos() q?0goL
{ aPb!-o{
try{ iTK1I0
output = new DataOutputStream(new FileOutputStream(tmpFile)); QiRzA4-zq
output.writeInt(nStartPos.length); 9QX{b+}"e
for(int i=0;i<nStartPos.length;i++) D3HB`{
{ Ys3C'Gc
// output.writeLong(nPos); G:&Q)_
output.writeLong(fileSplitterFetch.nStartPos); l{pF^?K
output.writeLong(fileSplitterFetch.nEndPos); Z$hxo)|
} U)l>#gf8
output.close(); /KV@Ce\
} dkn_`j\v
catch(IOException e){e.printStackTrace ();} B"B
catch(Exception e){e.printStackTrace ();} oNh .Zgg
} R1m18GHQ
,}|V'y
?<}qx`+%Q
//读取保存的下载信息（文件指针位置） .ZJh-cd
private void read_nPos() e| l?NXRX
{ 2'}2r ~6
try{ hs*:!&E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); {Y/
int nCount = input.readInt(); 02+^rqIx5
nStartPos = new long[nCount]; r-0 7!A
nEndPos = new long[nCount]; 1%:A9%O)t
for(int i=0;i<nStartPos.length;i++) Ud9\;Qse
{ ]E3g8?L
nStartPos = input.readLong(); ;kFp)*i
nEndPos = input.readLong(); 23fAc"@ B
} 9"aTF,'F/
input.close(); EXi+pm
} q_K1L
catch(IOException e){e.printStackTrace ();} 2>r.[
catch(Exception e){e.printStackTrace ();} @6Mo_4)O
} [&4y@
tw(2V$J
%B?5l^W@
private void processErrorCode(int nErrorCode) z>&D~0
{ V,"'k<y
System.err.println("Error Code : " + nErrorCode); GkO6r'MVE
} L7b{H22
@Uu\x~3y
y7Ub~qU
//停止文件下载 ZN1p>+oY!
public void siteStop() NR [VGZj
{ hPH7(f|c{g
bStop = true; GJ$,@
for(int i=0;i<nStartPos.length;i++) g-s@m}[T
fileSplitterFetch.splitterStop(); V:+bq`
0CR;t`M@
hh{liS% 10
} d"cfSH;h
} (M=Br
//负责部分文件的抓取 uXC?fMWp.
**FileSplitterFetch.java JQCwI`%i
*/ !K2[S J
package NetFox; RAxz+1JT
&sWyh[`P
PLyu1{1"z
import java.io.*; _aGdC8%[
import java.net.*; WI9.?(5q
7lpVK]
u rOGOa$
public class FileSplitterFetch extends Thread { .G]# _U
a]k&$
{3Rax5Ty
String sURL; //File URL ^/uGcz|.
long nStartPos; //File Snippet Start Position Rb0{t[IU
long nEndPos; //File Snippet End Position tvUvd(8w
int nThreadID; //Thread's ID R pbl)
boolean bDownOver = false; //Downing is over oGqv,[$qN
boolean bStop = false; //Stop identical ?x0yiV~dL
FileAccessI fileAccessI = null; //File Access interface 2uTa}{/%
QUDVsN#
Ss:,#|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +g[B &A!d+
{ K_aN7?#.v`
this.sURL = sURL; ._3NqE;
this.nStartPos = nStart; .R'i=D`Pz
this.nEndPos = nEnd; i=D,T[|>a
nThreadID = id; ^&.?kJM
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -T8 gV1*(<
} 1sJN^BvuG
lN'/Z&62
""d>f4,S
public void run() a3 x~B=E
{ e2fct|'
while(nStartPos < nEndPos && !bStop) X A|`wAGP
{ z,)sS<t(
&^H "T6
h~@+M5r,
try{ [ lW "M
URL url = new URL(sURL); \_E.%K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fz3*oJ'
httpConnection.setRequestProperty("User-Agent","NetFox"); /WfVG\NF
String sProperty = "bytes="+nStartPos+"-"; g@k9w{_
httpConnection.setRequestProperty("RANGE",sProperty); av?BpN"l
Utility.log(sProperty); S+G)&<a^
VZoOdR:d
}v,THj
InputStream input = httpConnection.getInputStream(); bEKLameKv
//logResponseHead(httpConnection); DO1{r/Ib.{
Oy&'zigJ
q#`^EqtUF
byte[] b = new byte[1024]; f zO8by
int nRead; -#6*T,f0P(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )mdNvb[*n
{ ];;w/$zke
nStartPos += fileAccessI.write(b,0,nRead); `1@[uWl
//if(nThreadID == 1) W<VHv"?V
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BT3O_X`u
} @E2nF|N
ntV>m*^
NO^t/(Z
Utility.log("Thread " + nThreadID + " is over!"); J"rwWIxO*
bDownOver = true; uN 62>
//nPos = fileAccessI.write (b,0,nRead); ?<'W~Rm6n
} 1,QZnF!.x
catch(Exception e){e.printStackTrace ();} z-5#bOABW
} 0)5Sx /5'
} 17)M.(qmuP
5-HJ&Q
,d>~='
//打印回应的头信息 U_'q-*W
public void logResponseHead(HttpURLConnection con) AFTed?(
{ Pfx71*u,
for(int i=1;;i++) _kN%6~+U
{ )c/y07er
String header=con.getHeaderFieldKey(i); !^fR8Tp9
if(header!=null) sVd_O[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z|*6fFE
Utility.log(header+" : "+con.getHeaderField(header)); L0b]^_tI
else }27Vh0v
break; Vor9 ?F&w
} IGT_ 5te
} :QV6z*#zD
ukf\*
]a#]3(o]}
public void splitterStop() FM"BTA:C
{ ~#_$?_/(
bStop = true; lMez!qx,=
} N>%KV8>{L
T1HiHvJ
Xl6ZV,1=n7
} 0DIM]PS
kZ-~ ;fBe
ws>Iyw.u
/* %@93^q[\2
**FileAccess.java NoZ4['NI\
*//文件访问(定位，写) :TYzzl43
package NetFox; 8;\tP29
import java.io.*; jnzz~:
KH>sCEt
f^sb0nU
public class FileAccessI implements Serializable{ HcVs(]tIW
EJaaW&>[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rqe_zyc&
RandomAccessFile oSavedFile; 6XL9 qb~X
long nPos; >ha Ixs`9
zMzf=~
b%f2"e0g
public FileAccessI() throws IOException 1=5'R/k
{ zRoEx1
this("",0); x ETVtq
} R 4QwWSBJ
e=)*O
ZX6=D>)u
public FileAccessI(String sName,long nPos) throws IOException MQH8Q$5D
{ O\F^@;]F6
oSavedFile = new RandomAccessFile(sName,"rw"); 0*IY%=i
this.nPos = nPos; :'rZZeb'
oSavedFile.seek(nPos); bA^:p3
} [-Tt11
%802H%+
YZ:'8<
public synchronized int write(byte[] b,int nStart,int nLen) m\Fb ,
{ _&Uo|T
int n = -1; M(WOxZ8
try{ `(Q_ 65y
oSavedFile.write(b,nStart,nLen); bc=u1=~w
n = nLen; ~K#_'Ldrd
} 4f[M$xU&h
catch(IOException e) %3#I:>si
{ LOUKUReE
e.printStackTrace (); $17 v,
} dms:i)L2
&T/q0bwd
e9hVX[uq
return n; <_{4-Q>S3#
} fRa-bqQ
^AjYe<RU}
,-IF++q
} ]G o~]7(5|
q{Ta?|x#
:f !=_^}
/* @uM3iO7&
**SiteInfoBean.java k#:@fH4{PA
*/ vl{_M*w ;
package NetFox; m57tOX
S}p&\w H
yZ~eLWz
public class SiteInfoBean { `_g?y)
L!b0y7yR
%=mwOoMk0L
private String sSiteURL; //Site's URL C|~JPcl
private String sFilePath; //Saved File's Path "K$Wh1<7
private String sFileName; //Saved File's Name %f> |fs
private int nSplitter; //Count of Splited Downloading File [cLU*:
IU'!?XVo
N" Jtg@w
public SiteInfoBean() MHr0CYyb.
{//nSplitter的缺省值为5 XG\a-dq[
//default value of nSplitter is 5 Vh.;p.!e
this("","","",5); OxHw1k
} Vq)gpR
D.&eM4MZ
~SR(K{nf#.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K0DXOVT\
{ E%2!C/+B
sSiteURL= sURL; hzuMTKH9
sFilePath = sPath; ND55`KT4
sFileName = sName; o +QzQ+ Z
this.nSplitter = nSpiltter; : `6$/DK
id#k!*$7
pJ$N@ID
} WP@JrnxO\`
<;,S"e
Th;gps%b
public String getSSiteURL() Z/6'kE{l
{ D@rn@N
return sSiteURL; ! N"L`RWD
} g"dZB2`C
o~.o^0Y
$YGIN7_Gg
public void setSSiteURL(String value) U3|&Jee
{ y%IG:kZ,
sSiteURL = value; @(,{_c]
} '^oGDlkr H
^;CR0.4
jY#(A23
public String getSFilePath() )*TW\v`B
{ kTiPZZI
return sFilePath; ]dGr1ncu
} 4<3?al&
i^s`6:rNu
ghJ,s|lH
public void setSFilePath(String value) 9?l?G GmQ
{ \{MrQ2jd
sFilePath = value; w[,?-Xm
} gSv[4,hXd
EDgob^>
8W1K3[Jj<
public String getSFileName() .y;\puNq
{ bDh:!M
return sFileName; 8%2rgA
} WDoKbTv
-M>K4*%K
5}d/8tS
public void setSFileName(String value) SN[L4}{
{ '!yS72{$2
sFileName = value; g@k#J"Q'[
} ,2 g M-
]4 K1%ZV
l#5~t|\
public int getNSplitter() :uIi ?
{ C$'D]fX
return nSplitter; I4o=6ts
} )4'x7Qg/
j2o1"
B \_d5WJ<
public void setNSplitter(int nCount) c+Q.?vJ
{ Uaus>Frx.T
nSplitter = nCount; U=&^H!LVY
} !e:iB7<
} (GCG/8s
_fcS>/<a
Fi mN?s
/* >Bc>IO
**Utility.java D`6iDit
*/ s}6+8fE"
package NetFox; ze`1fO|%
6iG(C.b
Zy^=fM
public class Utility { b2N6L2~V
6X/wdk
ev9;Ld
public Utility() "\e:h| .G
{ $}t=RW
sLb8*fak
1N8;)HLIBJ
} tAF]2VV(e
\tY"BC4.
//线程睡眠 i+g~ Uj}h
public static void sleep(int nSecond) ,V,f2W 4
{ $@_{p*q
try{ 93j{.0]X
Thread.sleep(nSecond); M\Se_
} a6%@d_A
catch(Exception e) PgMbMH
{ z~,mRgc$B
e.printStackTrace (); |6aJwe+*
} tQWWgLM
} oL]mjo=jN
\K;op2
//日志 089 k.WG
public static void log(String sMsg) -"=)z/S
{ nX|Q~x]
System.err.println(sMsg); H@GE)I>^@
} o\Uu?.-<
1BJ<m5/1%
6B0#4Qrv
public static void log(int sMsg) IV'p~t
{ c!It^*
System.err.println(sMsg); YTK^ijmU6x
} MaO"#{i
} gH[,Xx?BN!
Ojq]HM6f
zJ+3g!
/* mzWP8Hlw
**TestMethod.java l _+6=u
*/ OsQkA2=
package NetFox; #uSK#>H_!
e+.\pe\
l4rMk^>>
public class TestMethod { ldGojnS
W^es;5
VPt9QL(
public TestMethod() 4:7mK/Z
{ ///xx/weblogic60b2_win.exe {^#2=`:)O
try{ ?c]n^GvG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )tS-.PrA-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .h4\{|
SiteFileFetch fileFetch = new SiteFileFetch(bean); t V03+&jF
fileFetch.start(); kZLMtj-
} 4U=75!>
catch(Exception e){e.printStackTrace ();} Z<U>A
]ab#q=
XM/vDdR
} Tkw;pb
LH2PTW\b!6
}u%"$[I}
public static void main(String[] args) |S&5es-yW
{ EF#QH _X
new TestMethod(); 87V1#U^
} UL( lf}M
} j?6X1cMq
点击下载更多相关资料