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)); N ;n55N
} DGz}d,ie
for(int i=0;i<nEndPos.length-1;i++) =BV_?
{ Y9%zo~]-W'
nEndPos = nStartPos[i+1]; X*bOE}
} /nt%VLms%
nEndPos[nEndPos.length-1] = nFileLength; &4M,)Q (
} p}K+4z
} |y?W#xb
EU Oa8Z
O\@0o|NM
//启动子线程 ?8<R)hJa<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +4D#Ht7
for(int i=0;i<nStartPos.length;i++) ?fpI,WFu
{ xG'F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =}e{U&CX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), N]|)O]/[
nStartPos,nEndPos,i); "Gq%^^*
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8lCo\T5"
fileSplitterFetch.start(); :D !/.0
} )M56vyo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !Pd)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >k~3W> D
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _w%{yF6
nEndPos = " + nFileLength); 3Z%jx#
// fileSplitterFetch[nPos.length-1].start(); 99b"WH^3$y
/BM{tH
/AUX7 m.8
//等待子线程结束 Uo|T6N
//int count = 0; DM(c :+K-
//是否结束while循环 Cv]$w(k
boolean breakWhile = false; I5rAL\y-G
<2^ F'bQV
XIp>PcU^
while(!bStop) '^,|8A2
{ -}H EV#ev
write_nPos(); #[~f6s9D
Utility.sleep(500); zZPXI&,
breakWhile = true; V%FWZn^
v%E!
v-B&"XGy:
for(int i=0;i<nStartPos.length;i++) fZxEE~Q1
{ qtS+01o
if(!fileSplitterFetch.bDownOver) 8fb<hq<
{ 0?'v|5}
breakWhile = false; g+KuK`\N%
break; .:SY:v r
} :g)`V4%
} oJ0ZZu?{D
if(breakWhile) @t3&#I}mc
break; zj#8@gbh+
wf,w%n
_Xfn
//count++; 'w`9lIax
//if(count>4) KhNOxMZ
// siteStop(); j\uPOn8k
} oP`Qyk
1&utf0TX6q
$1bzsB|^
System.err.println("文件下载结束！"); HP[M"u
} Z!oq2,ia
catch(Exception e){e.printStackTrace ();} p-2PC{% t|
} SG-Xgr@
l1"*
I?Q[ZH:M
//获得文件长度 M}N[> ,2'
public long getFileSize() *#sY-Gd
{ kD_616
int nFileLength = -1; RH0J#6C/
try{ k6^!G"
URL url = new URL(siteInfoBean.getSSiteURL()); aQL$?,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 80Z'1'u0
httpConnection.setRequestProperty("User-Agent","NetFox"); !2]'S=Y
n~?n+\.&a
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int responseCode=httpConnection.getResponseCode(); vptBDfzz
if(responseCode>=400) 0GMov]W?i
{ OEXa^M4x
processErrorCode(responseCode); `fq#W#Pu
return -2; //-2 represent access is error )~ghb"K
} ~zL DLr=
t4r%EP|Zt
7uxUqM
String sHeader; \EQCR[7qu7
=4:]V\o):'
m 9.BU2.
for(int i=1;;i++) ko`.nSZ-k
{ ,?`Zrxe[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); N:&EFfg3
//Utility.log(in.readLine()); cxn*!TwDs
sHeader=httpConnection.getHeaderFieldKey(i); %p8#pt\$7
if(sHeader!=null) G"nGaFT~
{ V D.T=(
if(sHeader.equals("Content-Length")) .[C@p`DZ
{ T1g3`7C3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <@J0 770
break; Q> J9M`a
} 4s7&*dJ
} ID8u&:
else ((mR'A|`
break; Ula h!s
} bSj-xxB]e
} ]Wx?k7T
catch(IOException e){e.printStackTrace ();} ]lZg }7h
catch(Exception e){e.printStackTrace ();} .1A/hAdU
ND\M
ANq3r(
Utility.log(nFileLength); ['Y"6[1
u{%dm5
)h`8</#m{
return nFileLength; PHxNo)
} K2!GpGZu
x<\5Jrqt
{B7${AE
//保存下载信息（文件指针位置） 7,"y!\
private void write_nPos() F-%Hw
{ X|dlVNL8p
try{ i>%A0.9
output = new DataOutputStream(new FileOutputStream(tmpFile)); p&k%d, *
output.writeInt(nStartPos.length); A&D<}y/%
for(int i=0;i<nStartPos.length;i++) @|EWif|
{ g<g$c<sm
// output.writeLong(nPos); Ox9M![fC
output.writeLong(fileSplitterFetch.nStartPos); UM:]QbaIn
output.writeLong(fileSplitterFetch.nEndPos); V-kx=M"k
} ~'w]%rh!
output.close(); vE&K!k`
} kc/"
catch(IOException e){e.printStackTrace ();} o^v]d7I8b
catch(Exception e){e.printStackTrace ();} 9Xh1i`.D
} YT}ZLx
N^4CA@'{
bi[g4,`Z;
//读取保存的下载信息（文件指针位置） rUh2[z8:
private void read_nPos() $V,ZH* g
{ W#kd[Wi
try{ ~- eB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oaG;i51!
int nCount = input.readInt(); *JF7 B
nStartPos = new long[nCount]; PFjh]/=
nEndPos = new long[nCount]; WOi+y
for(int i=0;i<nStartPos.length;i++) SvQ!n4 $
{ = ( 4l
nStartPos = input.readLong(); N"s"^}M\
nEndPos = input.readLong(); l'7'G$v
} kK=f@l
input.close(); @cc}[Uw4B
} lC@wCgc
catch(IOException e){e.printStackTrace ();} BAojP1}+,
catch(Exception e){e.printStackTrace ();} XbIxGL
} QL:Qzr[
-J>f,zA
ndu$N$7+
private void processErrorCode(int nErrorCode) %k @4}M>
{ PLq]\y
System.err.println("Error Code : " + nErrorCode); =!u]t&yv
} .rQcg.8/B
|E&|6h1
VFq7nV/O
//停止文件下载 (-xVW#39
public void siteStop() e5(c,,/
{ W&HxMi
bStop = true; Vi#[kn'
for(int i=0;i<nStartPos.length;i++) cZ3A~dTOR
fileSplitterFetch.splitterStop(); `+i/rc1.
.E;}.X
0E9 lv"3o
} #'. '|z
} eoJ*?v
//负责部分文件的抓取 ^UBzX;|p
**FileSplitterFetch.java Y$_^f*sFn
*/ k ~4o`eA
package NetFox; pm2]
JFq<sY!
D;z!C ys
import java.io.*; iD/+#UTY
import java.net.*; \H 5t-w=
Y.kc,~vYL
WR_B:%W.
public class FileSplitterFetch extends Thread { -`$J& YU
<pM6fI6BD
&~'i,v|E
String sURL; //File URL `Om W#\
long nStartPos; //File Snippet Start Position #mD_<@@
long nEndPos; //File Snippet End Position 0^)~p{Zh
int nThreadID; //Thread's ID OS1f}<
boolean bDownOver = false; //Downing is over `|mV~F|
boolean bStop = false; //Stop identical ,+X:#$
FileAccessI fileAccessI = null; //File Access interface 8:2Vib$
eN`G2eE
PP]7_h^2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {asq[;]
{ v=cX.^L
this.sURL = sURL; OTNI@jQ)
this.nStartPos = nStart; v^ v \6uEP
this.nEndPos = nEnd; eI%kxqc
nThreadID = id; dF5y' R'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w-C%,1F,/
} +G+1B6S
d^`;tD
UID`3X
public void run() y1[@4TY]
{ "p+JME(
while(nStartPos < nEndPos && !bStop) }}bMq.Q'
{ [.6bxK
4vNH"72P
8L]Cc!~
try{ f8G<5_!K_
URL url = new URL(sURL); ?$y/b}8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qn'TIE.
httpConnection.setRequestProperty("User-Agent","NetFox"); Mb45UG#2
String sProperty = "bytes="+nStartPos+"-"; b$- g"F
httpConnection.setRequestProperty("RANGE",sProperty); F!w|5,)
Utility.log(sProperty); s#8T46?
DyA1zwp}
NiQ Y3Nj
InputStream input = httpConnection.getInputStream(); y\[q2M<
//logResponseHead(httpConnection); L+eK)Q
b *3h}n;
j?g#8L;W\w
byte[] b = new byte[1024]; +}Mm5^6*
int nRead; "-j96 KD
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BuUM~k&SY
{ NG23
nStartPos += fileAccessI.write(b,0,nRead); = uepg@J
//if(nThreadID == 1) P*OT&q
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Om_ "X6
} (+<66 TO
s6#e?5J
THB[(3q
Utility.log("Thread " + nThreadID + " is over!"); A PrrUo
bDownOver = true; ~yV?*"Hi
//nPos = fileAccessI.write (b,0,nRead); qT&zg@m
} E*kZGHA
catch(Exception e){e.printStackTrace ();} &>R:oYN
} d`%7Pk
} 9l:[jsk<d
P"Z1K5>2L
>%slzr
//打印回应的头信息 }mI0D>n
public void logResponseHead(HttpURLConnection con) Vup|*d2r0E
{ zAev@+.ld
for(int i=1;;i++) {xTh!ih2-
{ ~:|V,1
String header=con.getHeaderFieldKey(i); cIK4sOTJ&
if(header!=null) FMzG6nrdBN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); NzN"_ojM
Utility.log(header+" : "+con.getHeaderField(header)); ~-uDN)
else fu-,<m{
break; 4vkqe6
} QIJ/'72
} {~G~=sC$
rV?@Kgxi
)n[=)"rf
public void splitterStop() ^g"p}zf L"
{ }wI+eMr
bStop = true; <'BsQHI
} ,p!IFS`
Lf%}\0:
-8dz`o}
} YN7`18u
Prc1U)nfo
Md8<IFi9]Q
/* {.DY\;Q
**FileAccess.java QXO~DR1
*//文件访问(定位，写) %|>D{q6C
package NetFox; Y^;izM}
import java.io.*; u1d%wOY
+Hp`(^(
;vbMC74J#
public class FileAccessI implements Serializable{ CC3M7|eO3
e<FMeg7n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8!@}\6qM
RandomAccessFile oSavedFile; 17 0r5
long nPos; ;:>q;%
!\O!Du
2^w{Hcf
public FileAccessI() throws IOException @2-;,VL3
{ L]&y[/\E1
this("",0); 8U4In[4
} !4 lN[
#\ysn|!J,
" SP6o
public FileAccessI(String sName,long nPos) throws IOException |x>5T}
{ [F(iV[n%
oSavedFile = new RandomAccessFile(sName,"rw"); `U>2H4P
this.nPos = nPos; 9\=SG"e(
oSavedFile.seek(nPos); Q&"oh
} NzeiGj
]&`=p{Z
v(Sh+p
public synchronized int write(byte[] b,int nStart,int nLen) rw0s$~'
{ E\cX
int n = -1; o)DO[
try{ gr{*wYL
oSavedFile.write(b,nStart,nLen); W/~q%\M {
n = nLen; ya,-Lt
} In+2~Jw/2!
catch(IOException e) i&DUlmt)f
{ ?32i1F!
e.printStackTrace (); 8F's9c,
} U\-.u3/
' ~fP#y
XdOntP*a
return n; CVEo<Tz
} #uCfXJ-
>g@@ yR,
"ctZ"*
} cR*~JwC:
aVr=7PeF
DnW/q
/* 9RkNRB)8
**SiteInfoBean.java Ae"|a_>fMI
*/ tYSfeU
package NetFox; 036QV M$
&fU48n1Uh
)p:+!sX(
public class SiteInfoBean { )V*`(dn'zm
/g!Xe]Ss
CJs ~!ww
private String sSiteURL; //Site's URL h]&~yuI>
private String sFilePath; //Saved File's Path (XFF}~>B.
private String sFileName; //Saved File's Name yMD0Tj5ZQ
private int nSplitter; //Count of Splited Downloading File >Ad`_g6Wew
'Z#>K*
[~`p~@\+
public SiteInfoBean() P.1Z@HC
{//nSplitter的缺省值为5 }Gx@1)??
//default value of nSplitter is 5 D>Rlm,U
this("","","",5); Q:b0!
} 7m?fvKy
VRSBf;?
&yOl}?u
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S?OCy4dk:
{ Q|2*V1"r<2
sSiteURL= sURL; ~lqNWL^l
sFilePath = sPath; Z,M2vRj"qT
sFileName = sName; >!tfvM2X{
this.nSplitter = nSpiltter; 6Lg#co}9
4p6T0II_$
C^,J6;'
} `G:hC5B
B+pLW/4l
X gtn}7N.
public String getSSiteURL() Y@T$O<*
{ lZ <D,&
return sSiteURL; aOsc_5XDR;
} Rz6kwh=q
N$.ls48a4-
ilZ5a&X;
public void setSSiteURL(String value) w]V684[>
{ I'N!j>5oX
sSiteURL = value; ,_=LV
} \nL@P6X
'GO*6$/
.SOCWznb
public String getSFilePath() X?/32~\
{ mGoC8t}iP
return sFilePath; K 6,c||#<
} !FB2\hiM
d(|4 +^>
oU*e=uehj
public void setSFilePath(String value) PQz[IZ
{ C]ax}P>BQ
sFilePath = value; k ,r*xt
} s5MG#M 9
Q trU_c2k
LJt5?zQKrW
public String getSFileName() <7/7+_y
{ T?`Ha\go
return sFileName; BAT.>
} .cmhi3o4
`/WOP`'zM
H$ :BJ$x@
public void setSFileName(String value) -Q ];o~
{ [DTe
sFileName = value; <Oy2JjY
} &[yYgfsp
zhyf}Ta'
Q2Uk0:M
public int getNSplitter() m+ #G*
{ )]m4FC:
return nSplitter; i"E_nN"V
} 87KSV"IU8
KQ(S\
Kf$6D 79#
public void setNSplitter(int nCount) ^lK!tOeO
{ zNEN[
nSplitter = nCount; Us>
} u(ETc*D]
} zXwdU58
Oj2=&uz
&@PAv5iNf
/* l[nf"'
**Utility.java =H}}dC<)
*/ Ie8K[ >
package NetFox; 'w|N} 4
vQDR;T"]
90H/Txq
public class Utility { )>;387'Y
|I.5]r-EK
|(Xxi
public Utility() 'sk M$jr
{ i}))6
V:AA{<
&kH7_Lz
} :/}=s5aQl/
S7R*R}
//线程睡眠 HDs8M
public static void sleep(int nSecond) z qd1G(tO
{ KXu1%`x=%Z
try{ Nk9w; z&
Thread.sleep(nSecond); =]<X6!0mR
} mDWRYIuN
catch(Exception e) Maiyd
{ #"o`'5
e.printStackTrace (); AJP-7PPD
} _Vr}ipx-k
} +^4HCyW
eHyIFoaC/
//日志 1L3 $h0i
public static void log(String sMsg) 7TZ,bD_
{ /T 4GPi\lg
System.err.println(sMsg); ORfMp'uP=
} h>/L4j*Z
pJQ_G`E
R~#&xfMd.
public static void log(int sMsg) 3C#Sr6
{ 36 ]?4, .
System.err.println(sMsg); (%{!TJgZR
} &tlU.Whk+
} \YH*x`
!\q'{x5C
_+&/P&
/* 4uv*F:eo
**TestMethod.java DM{Z#b]
*/ XeAH.i<
package NetFox; }wGy#!CSza
e~$aJO@B.R
kg$w<C@#"
public class TestMethod { YA8ZB&]En/
-.UUa
j|y"Lcq
public TestMethod() FF30VlJ
{ ///xx/weblogic60b2_win.exe ^=w){]G
try{ <\?dPRw2>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &3YXDNm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .[vYT.LE
SiteFileFetch fileFetch = new SiteFileFetch(bean); R^6^{q
fileFetch.start(); M`|E)Y
} q>VvXUyK,
catch(Exception e){e.printStackTrace ();} -$(2Z[
<+ckE2j
Jrx]/CM
} L!:;H,
Bvz& p)(
p+:MZP -%(
public static void main(String[] args) ?"T *{8
{ ]hY4 MS
new TestMethod(); uBo~PiJ2"
} ?qczMck_
} _z&H O
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