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)); Au {`oxD
} X!@Gv:TD
for(int i=0;i<nEndPos.length-1;i++) q&+GpR
{ 6*e:ey U
nEndPos = nStartPos[i+1]; 7J_H Ox#
} k$hWR;U
nEndPos[nEndPos.length-1] = nFileLength; m=R4A4Y7
} U>>J_2
} o)$sZ{` ="
67e1Y@Xu
]KfHuYjM
//启动子线程 DN!EsQ6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?vhW`LXNB
for(int i=0;i<nStartPos.length;i++) 5rc<ibGh
{ {BJxRH"&6*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ELm#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), hZpFI?lqc\
nStartPos,nEndPos,i); Bg3^BOT
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @=9QV3D
fileSplitterFetch.start(); Nb$)YMbA
} `1P &
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !vsUL-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 0ul2rZc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Pvtf_Qo^
nEndPos = " + nFileLength); ' ft |
// fileSplitterFetch[nPos.length-1].start(); >Nov9<p
R(:q^?
)a.U|[:y[+
//等待子线程结束 `aJ[ !O
//int count = 0; 2@ad!h
//是否结束while循环 ,+JAwII>O
boolean breakWhile = false; ;c'jBi5W
F8pLA@7[
| o?@Eh
while(!bStop) /5o~$S
{ /q>"">
write_nPos(); @M(vaJB8u
Utility.sleep(500); hGpaHY>My
breakWhile = true; v/kYyz
eVy,7goh
}NUP[%
for(int i=0;i<nStartPos.length;i++) 8T%z{A1T
{ old}}>_
if(!fileSplitterFetch.bDownOver) <mpkkCl,
{ ;xb:{?
breakWhile = false; j3FDGDrg
break; k`N)-`O7
} ON$u581 y
} AttDD{Ta
if(breakWhile) Q%85,L^U
break; K(_nfE{
<5nz:B/
ub-ZrC'
//count++; <AB]FBo(
//if(count>4) {6n B83BB
// siteStop(); O*30|[
} N~a?0x
{AB0 PM;-
l{;vD=D
System.err.println("文件下载结束！"); ua2SW(C@
} n\d-^ml
catch(Exception e){e.printStackTrace ();} YpAjZQZ,
} s]}P jh8
fHM<6i<C
D@!#79:)
//获得文件长度 0"ZRJl<)[I
public long getFileSize() W#ev
{ 2?HLEiI1
int nFileLength = -1; .i&]VGv
try{ "6.kZ$`%
URL url = new URL(siteInfoBean.getSSiteURL()); dfk=%lZYd9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '(ql7
httpConnection.setRequestProperty("User-Agent","NetFox"); q),yY]5
EKgTRRW
HogT#BMs
int responseCode=httpConnection.getResponseCode(); C EAwQH
if(responseCode>=400) M[SWMVN{
{ 0kmZO"K#e
processErrorCode(responseCode); 'sJYt^
return -2; //-2 represent access is error "/wZtc
} aQcJjF5x
G!wFG-Y}
X+iUT
String sHeader; b^rPw@
z`'{l{
XO219
for(int i=1;;i++) YX-G>.Pc
{ 2b2/jzO}J
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hbn2(e;FZ
//Utility.log(in.readLine()); IRD?.K]*
sHeader=httpConnection.getHeaderFieldKey(i); g&&5F>mF
if(sHeader!=null) {8'I+-
{ iFpJ/L
if(sHeader.equals("Content-Length")) )p 2kx
{ IE,xiV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %I?uO( @
break; `Fnt#F}
} u|i.6:/=
} r6JdF!\d
else Q/L:0ovR
break; /djr_T
} j#zUO&Q@
} dy`K5lC@
catch(IOException e){e.printStackTrace ();} fpu^
catch(Exception e){e.printStackTrace ();} K8f;AK
r+ k5Bk'
i#=s_v8
Utility.log(nFileLength); O6 bB CF;
|cUTP!iy
^pIT,|myY7
return nFileLength; 7ZqC1
} \= =rdW-
+<7`Gn(n3
a;8q7nC
//保存下载信息（文件指针位置） cl/}PmYIZ
private void write_nPos() r< sx On
{ |aIY
try{ `2()Vf
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6O>NDTd%
output.writeInt(nStartPos.length); -lAX-W0
for(int i=0;i<nStartPos.length;i++) ET.c8K1f
{ \%g# __\
// output.writeLong(nPos); t&*X~(Yb!
output.writeLong(fileSplitterFetch.nStartPos); -YPUrU[)
output.writeLong(fileSplitterFetch.nEndPos); wak_^8x
} rzsAnLxo
output.close(); *#\da]"{
} rI23e[
catch(IOException e){e.printStackTrace ();} {d|e@`"T
catch(Exception e){e.printStackTrace ();} W!MO}0s
} Y`.FSs
B}Qpqa=_c
ezS@LFaA
//读取保存的下载信息（文件指针位置） f_I6g uDPz
private void read_nPos() xJlf}LEyF
{ * `1W})
try{ ~|QhWgq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Wo+fMn(O
int nCount = input.readInt(); ER-X1fD
nStartPos = new long[nCount]; 6R1}fdHvP
nEndPos = new long[nCount]; 1CXO=Q
for(int i=0;i<nStartPos.length;i++) gE;r;#Jt4
{ mO%F {'
nStartPos = input.readLong(); qy|[V
nEndPos = input.readLong(); z3>ldT
} MROe"Xj
input.close(); "&lQ5]N.%
} H!PMb{e
catch(IOException e){e.printStackTrace ();} ]jQj/`v1
catch(Exception e){e.printStackTrace ();} wA$ JDf)Vg
} jJc:%h$|2
-q'G]}
X?kw=x{2P
private void processErrorCode(int nErrorCode) F5s Pd
{ X2\1OWR0
System.err.println("Error Code : " + nErrorCode); AYb-BaIc
} a/p} ?!\
Q#M@!&
Pr|BhX
//停止文件下载 ,E ]vM&
public void siteStop() O1xK\ogv
{ #$-{hg{
bStop = true; *5T^wZpj)
for(int i=0;i<nStartPos.length;i++) ^E-BB 6D
fileSplitterFetch.splitterStop(); 7\.{O$Q
x)GpNkx:
GP<PU
} CvkZ<i){
} ;xqN#mqq
//负责部分文件的抓取 N5K\h}'%
**FileSplitterFetch.java Z8 eB5!$
*/ ]40@yrc
package NetFox; ,r_%p<lOFu
?/3'j(Gk
JO[7_*s
import java.io.*; f N_8HP6&
import java.net.*; n[+$a)$8
:}0>IPW-V
[8%R*}
public class FileSplitterFetch extends Thread { {wJ8% ;Z7
C"7-lz
(Y!{ UNq5
String sURL; //File URL ngLpiU0H&
long nStartPos; //File Snippet Start Position 2e_m>I
long nEndPos; //File Snippet End Position 2-$O$&s.
int nThreadID; //Thread's ID X^o0t^
boolean bDownOver = false; //Downing is over y\?NB:=%
boolean bStop = false; //Stop identical z*,J0)<Q
FileAccessI fileAccessI = null; //File Access interface 0^('hS&
9Ib#A
`En>o~L;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y?Cq{(
{ e|1.-P@
this.sURL = sURL; Ah:d2*SR4
this.nStartPos = nStart; o$q})!
this.nEndPos = nEnd; Gov]^?^D-
nThreadID = id; M4}b lh#
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [Fk|%;B/~
} 2]:Z7Ji
~8 S2BV3@
eXA@J[-M:
public void run() 4ux^K:z
{ )`5=6i
while(nStartPos < nEndPos && !bStop) &iI5^b-P
{ ,hSTR)
SX1w5+p$C
WJU[+|J
try{ JavSR1_
URL url = new URL(sURL); N!lQ;o'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); vw2yOLRX
httpConnection.setRequestProperty("User-Agent","NetFox"); Q@(tyW+8U@
String sProperty = "bytes="+nStartPos+"-"; 2%_UOEayU
httpConnection.setRequestProperty("RANGE",sProperty); ,z5B"o{Et
Utility.log(sProperty); L)"E_
FE'F@aS\
1|XC$0
InputStream input = httpConnection.getInputStream(); b}HwvS:
//logResponseHead(httpConnection); CaB@,L
S; Fj9\2)I
wX+KW0|>
byte[] b = new byte[1024]; jJqq:.XqB8
int nRead; hMnJH_siY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) wl5+VC*l0
{ wA< Fw )
nStartPos += fileAccessI.write(b,0,nRead); BTnrgs#[
//if(nThreadID == 1) '*=kt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3)*Twqt
} 3[Z7bhpV
\Z8:^ct.P
_Gtq]`y
Utility.log("Thread " + nThreadID + " is over!"); HDQH7Bs
bDownOver = true; 8i~n;AhDs
//nPos = fileAccessI.write (b,0,nRead); vYNu=vnM
} \Xpq=2`
catch(Exception e){e.printStackTrace ();} @)x8<
} $:IEpV{
} f#3!Q!C^
m{?uR.O
U2CCjAgRs
//打印回应的头信息 St|B9V?eEB
public void logResponseHead(HttpURLConnection con) qr'P0+|~5
{ v=J[p;H^H
for(int i=1;;i++) eh /QFm 4
{ M/evZ?uis
String header=con.getHeaderFieldKey(i); Oi4y~C_Xd
if(header!=null) e)#f`wM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NR.YeKsBq
Utility.log(header+" : "+con.getHeaderField(header)); q[5&
else f9a_:]F
break; ><w=
} cz;gz4d8
} I?X!v6
F.$NYr/|y
}%Vx2Q
public void splitterStop() RxUzJ
{ <2ymfL-q
bStop = true; "yf#sEabV
} d: LP8
:<PwG]LO
[DSD[[ z[
} S*'
7q@>d(xho
ZUK'z
/* !8}x6
**FileAccess.java !9g>/9h
*//文件访问(定位，写) hM[QR'\QS
package NetFox; %y[ t+)!E
import java.io.*; ByivV2qd{
56!/E5qgW
IgNL1KRD
public class FileAccessI implements Serializable{ dFzlcKFFD
aP`V
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A[Pz&\@
RandomAccessFile oSavedFile; w<jlE8u
long nPos; @Rs3i;"W
=x-@-\m
50HRgoP5Y
public FileAccessI() throws IOException $zD}hO9
{ &-2i+KjEX
this("",0); xO<Uz"R
} &\ \)x.!
*Ry{}|_8
8jjq)d4#
public FileAccessI(String sName,long nPos) throws IOException 97\9!)`,
{ f{ER]U
oSavedFile = new RandomAccessFile(sName,"rw"); a9niXy}a(
this.nPos = nPos; <69Uq8GI
oSavedFile.seek(nPos); by@}T@^\
} `>N_A!pr`
.!yw@kg
7!jbID~
public synchronized int write(byte[] b,int nStart,int nLen) <j&LC /]o
{ U`)o$4Bq
int n = -1; KpSho<
try{ 99u9L)
oSavedFile.write(b,nStart,nLen); ? yek\X
n = nLen; {3){f;b
} HV\l86}
catch(IOException e) u ioBId
{ ctT6va
e.printStackTrace (); pHv~^L%=
} sFa5#w*>
'/~j!H4q9
B,avI&7M;S
return n; Jwe9L^gL
} KV]8o'
/><+[\q4LM
{n-6e[
} MNVOloA
m+'vrxTY
!)+8:8H'
/* 6rg?0\A<
**SiteInfoBean.java KQ2jeJ/pj
*/ +"F9yb
package NetFox; JVt(!%K}&
nWb0S
D/Hob
public class SiteInfoBean { 5$Da\?Fpn
q}MPl2
]}HuK#
private String sSiteURL; //Site's URL mrId`<L5l{
private String sFilePath; //Saved File's Path 6ujePi <U
private String sFileName; //Saved File's Name #P5tTCM
private int nSplitter; //Count of Splited Downloading File !/wR[`s9w
E'wJ+X9 +
:y8wv|m
public SiteInfoBean() TYN~c(
{//nSplitter的缺省值为5 3e7P w`gLl
//default value of nSplitter is 5 \&.]!!Q
this("","","",5); 1k?k{Ri
} iES?}K/q
iU9>qJ]
GEQ3r'B|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0 V3`rK
{ e QGhX(
sSiteURL= sURL; t%Hy#z1W_
sFilePath = sPath; \SQwIM
sFileName = sName; (OT&:WwW
this.nSplitter = nSpiltter; zcE[wM
GMJ</xG
p7eRAQ\'
} e9@7GaL`"S
8nQjD<-
0VBbSn}Z<
public String getSSiteURL() jce^Xf
{ ,+hH|$
return sSiteURL; K3On8
} |A%Jx__
'v:%} qMv
>nOU 8
public void setSSiteURL(String value) LJ+Qe%|
{ mOE%:xq9-
sSiteURL = value; L-QzC<[F/
} 1Kc[).O1
VdetY\
WPu{ ]<pl
public String getSFilePath() eh5j
{ N]iu o.
return sFilePath; j@4AY}[tX
} >4@/x{{
QM'Db`B
q#!]5
public void setSFilePath(String value) <C6*-j1oz
{ *D6X&Hg&5
sFilePath = value; (M,IgSn9
} %?WR9}KU0
u[;,~eB%w
:d,]BB
public String getSFileName() (@"5:M
{ ne(zGJd
return sFileName; ]|PDsb"e
} @ky<5r*JU(
#FQkwX'g
S#wy+*
public void setSFileName(String value) SB#Y^!
{ |A0)-sVZ
sFileName = value; Yl#|+xYA5[
} cN(Toj'`
p3R: 3E6p
svTKt%6X
public int getNSplitter() ^^C@W?.z
{ yl'@p5n
return nSplitter; Y!C8@B$MR3
} LqA&@
WXzSf.8p|
ejjL>'G/|%
public void setNSplitter(int nCount) ZgD%*bH*B
{ FC BsC#
nSplitter = nCount; mIy|]e`SJ
} N(W;\>P
} qVDf98
@V>BG8Y
!/;/ X\d
/* Zl4X,9Wt
**Utility.java t5"g9`AL
*/ UG5AFZ\
package NetFox; "ytPS~
m:
_hz}I>G@B
public class Utility { V~%C me
a#L:L8T;j
5zf bI
public Utility() #FNSE*Y
{ o,D7$WzL
<jwQ&fm)/R
"7X[@xX@
} {k"t`uo_
9>I&Z8J$M
//线程睡眠 (O@fgBM
public static void sleep(int nSecond) 2^;zj0]Rt
{ )A1u uW (
try{ ??u*qO:p
Thread.sleep(nSecond); ^_rBEyz@
} Nm.G,6<J
catch(Exception e) yPXa
{ c`E0sgp
e.printStackTrace (); aB*'DDlx"r
} B}U:c]
} mY1Gm|
;.'\8!j
//日志 MX)mm^A
public static void log(String sMsg) ;b6h/*;'
{ ALY3en9,
System.err.println(sMsg); 4A{6)<e
} q4y sTm
)kpNg:2p
$3'xb/3|
public static void log(int sMsg) W_bp~Wu
{ GnFm*L
System.err.println(sMsg); qOs'Ljx6l
} ~cL)0/j}
} 49iqrP'
E3"j7y[S
L4t(Y7
/* ?;xL]~Q~1
**TestMethod.java %5yP^BL0
*/ ;ZtN9l
package NetFox; fG_<HJS(~
?l>Ra0
D_)N!,i
public class TestMethod { !(8)'<t9
IDK~ (t
Xf%vfAf
public TestMethod() $No^\.mV
{ ///xx/weblogic60b2_win.exe _fM=J+
try{ f>zd,|)At
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P|tNmv[;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); %u!)1oOIz
SiteFileFetch fileFetch = new SiteFileFetch(bean); LFX[v
fileFetch.start(); 4L_AhX7
} n3" @E<rW
catch(Exception e){e.printStackTrace ();} 7I=vgT1F
qp{3I("_
V M{Sng
} JKY
lKBI3oYn
q5G`N>"V
public static void main(String[] args) x,j%3/J^2
{ 3S=$ng
new TestMethod(); W!R7D%nX
} .$U=ngj\t
} Sah!|9
点击下载更多相关资料