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)); FU(}=5n
} zhA',p@K?_
for(int i=0;i<nEndPos.length-1;i++) "doU.U&u
{ o! 2n}C
nEndPos = nStartPos[i+1]; 3!"b guE
} u_p7Mcb
nEndPos[nEndPos.length-1] = nFileLength; |`k1zc)9
} RvPniT(<?
} PV]k3&y
w`.T/
X#p o|,Q
//启动子线程 G>[ NZE
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; BS-:dyBw
for(int i=0;i<nStartPos.length;i++) ! =\DC,-CB
{ s#+"5&!s
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hs{&G^!jo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), <wUD
nStartPos,nEndPos,i); (?!(0Ywbg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qlz9&w
fileSplitterFetch.start(); ;e~{TkD
} Msv*}^>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /jZaU`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); yUD_w
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y0Hq+7x
nEndPos = " + nFileLength); C>Omng1>^
// fileSplitterFetch[nPos.length-1].start(); 2xL!PR-
:_o] F
_uO!N(k.
//等待子线程结束 Q{.{#G
//int count = 0; -'O Q-5
//是否结束while循环 >/!7i3Ow-
boolean breakWhile = false; 55>" R{q
+7i7`'9pd
I=4Xv<F
while(!bStop) 8 l'bRyuS
{ >bX-!<S
write_nPos(); o273|*
Utility.sleep(500); e(OwS?K
breakWhile = true; D4=..;
IdV,%d{
,YP1$gj
for(int i=0;i<nStartPos.length;i++) "<PoJPh
{ [):{5hMA
if(!fileSplitterFetch.bDownOver) 97qtJ(ESI
{ 5"-una>D
breakWhile = false; } * ?n?'
break; h*;g0QBkl
} b(PHZCy#
} Sk6b`W7$
if(breakWhile) ;mf4U85
break; =_$XP
dN$ 1$B^k
a"0B?3*r46
//count++; kfMhw M8kP
//if(count>4) QHHW(InG<
// siteStop(); ZdE>C
} a)3O? Y
Vl5SL{+D
_o@(wGeu#
System.err.println("文件下载结束！"); G$?|S@I,
} 4zo4H~@gk
catch(Exception e){e.printStackTrace ();} ~q0I7M
} [,OJX N-4s
W]@gQ(Ef
'GEBxNH:
//获得文件长度 _u:>1]
public long getFileSize() Qqd6.F
{ pP|,7c5
int nFileLength = -1; UJee&4C-y
try{ /6+1{p
URL url = new URL(siteInfoBean.getSSiteURL()); !cq=)xR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "C_T]%'Wm
httpConnection.setRequestProperty("User-Agent","NetFox"); !GlnQ`T
5x*5|8
f,Sth7y
int responseCode=httpConnection.getResponseCode(); ksB
if(responseCode>=400) ES^>[2Y
{ ;j>*;Q`
processErrorCode(responseCode); 0lX)Cl
return -2; //-2 represent access is error mgi,b2
} [<]Y+33
Uby,Tu
<U@P=G<t
String sHeader; $7Jfb<y
nkCecwzr-
Sg-g^dIN1
for(int i=1;;i++) ,\BVV,
{ cU7rq j_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Yta1`
//Utility.log(in.readLine()); -Qg 2qN2{
sHeader=httpConnection.getHeaderFieldKey(i); |0tg:\.
if(sHeader!=null) ./5jx2V
{ :z B}z^8-
if(sHeader.equals("Content-Length")) Ihdu1]~R{
{ Gs+\D0o!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ANckv|&'v
break; 4rI:1yGt@
} T#\p%w9d
} M,crz
else q^Z~IZ8IT
break; 'Pf_5q
} LYp'vZ!
} Nc{]zWL9
catch(IOException e){e.printStackTrace ();} Uh>.v |P6
catch(Exception e){e.printStackTrace ();} |r5e{
sC% b~
-@rxiC:Q
Utility.log(nFileLength); ?Q@L-H`
HV ;;
D,MyI#
return nFileLength; Ej' 7h~=v
} *Wzwbwg
h2"9"*S1
-g:lOht
//保存下载信息（文件指针位置） DKh}Y !Q=:
private void write_nPos() L'>s(CR
{ 1<`9HCm
try{ w|=gSC-o
output = new DataOutputStream(new FileOutputStream(tmpFile)); N6h1|_o
output.writeInt(nStartPos.length); 6MuWlCKF8
for(int i=0;i<nStartPos.length;i++) (YIhTSL"]
{ Z)/6??/R
// output.writeLong(nPos); Am=wEu[b
output.writeLong(fileSplitterFetch.nStartPos); \@i=)dA
output.writeLong(fileSplitterFetch.nEndPos); =K:(&6f<t
} \ZS\i4
output.close(); , 7Xqte
} *9J1$Wa
catch(IOException e){e.printStackTrace ();} hL0]R,t;'
catch(Exception e){e.printStackTrace ();} (zY *0lN
} ,~- ?l7
v51EXf
U|8[#@r
//读取保存的下载信息（文件指针位置） So#dJ>
private void read_nPos() _().t5<
{ r:-WzH(Ms
try{ NH'iR!iGo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); tevQW
int nCount = input.readInt(); GJX4KA8J
nStartPos = new long[nCount]; \k;U}Te<
nEndPos = new long[nCount]; k5a\Sq}
for(int i=0;i<nStartPos.length;i++) e$/&M*0\f
{ h2% J/69
nStartPos = input.readLong(); ;+ G9-
nEndPos = input.readLong(); ^|aNG`|O
} @44P4?;
input.close(); J/t!-!
} }w@gj"\H
catch(IOException e){e.printStackTrace ();} aM$\#Cx
catch(Exception e){e.printStackTrace ();} eaQ90B4
} f/ajejYo?,
6yI}1g
k,rWa
private void processErrorCode(int nErrorCode) _9NVE|c;
{ ET)>#zp+s
System.err.println("Error Code : " + nErrorCode); a+41Ojv (
} J='W+=N
0N{+y}/G
i&A%"lOI9
//停止文件下载 Ib1e#M3
public void siteStop() O6iCZ
{ W (`c
bStop = true; azo0{`S?
for(int i=0;i<nStartPos.length;i++) < A?<N?%o
fileSplitterFetch.splitterStop(); snYr9O[E6
Q2eXK[?*
|) Pi6Y
} t8&q9$
} Jf)3< ~G
//负责部分文件的抓取 [?KJ9~+0
**FileSplitterFetch.java b{RqwV5P
*/ fYBH)E
package NetFox; YUscz!rM
Gy!P,a)z
55-D\n<
import java.io.*; 9cQ_mgch
import java.net.*; S5_t1wqBJ
wVqd$nsY"
[9V]On
public class FileSplitterFetch extends Thread { F}U5d^!2
Fc8E Y*
`5'2Hg+
String sURL; //File URL t\r:E2 O
long nStartPos; //File Snippet Start Position \&a.}t
long nEndPos; //File Snippet End Position . uR M{Bs
int nThreadID; //Thread's ID m=TJDr-
boolean bDownOver = false; //Downing is over g_w&"=.jBq
boolean bStop = false; //Stop identical aI(>]sWJ
FileAccessI fileAccessI = null; //File Access interface ,+._;[k
5j eO"jB
]` ]g@v
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =Ikg.jYq&F
{ kq-6HDR
this.sURL = sURL; e"Rm_t
this.nStartPos = nStart; 5)'P'kVi7.
this.nEndPos = nEnd; o2=A0ogz?
nThreadID = id; K=6UK%y A
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \DA$6w\\
} XoR>H4xh
+y&d;0!
?t rV72D
public void run() `.=sTp2rbc
{ rg5]&<Vq8
while(nStartPos < nEndPos && !bStop) j'GtgT
{ j7 d:v7+_
J!h^egP
'<@=vGsye
try{ dTGA5c
URL url = new URL(sURL); 7zDiHac
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); = .oHnMX2M
httpConnection.setRequestProperty("User-Agent","NetFox"); *Oo &}oAj
String sProperty = "bytes="+nStartPos+"-"; }nud
httpConnection.setRequestProperty("RANGE",sProperty); NQ9Ojj{#
Utility.log(sProperty); w#(RW7":F
[f!O6moR6
c8A`<-\MfB
InputStream input = httpConnection.getInputStream(); V5"HwN+`
//logResponseHead(httpConnection); O8|*M "
b |7ja_
1;&;5
byte[] b = new byte[1024]; =Q(vni83<
int nRead; 0{) $SY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4vdNMV~
{ +.Bmkim
nStartPos += fileAccessI.write(b,0,nRead); &uM^0eM
//if(nThreadID == 1) 7Kf}O6nE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (~s|=Hxq|-
} f9TV%fG?
Cca0](R*&
8o-bd_
Utility.log("Thread " + nThreadID + " is over!"); _:J*Cm[q
bDownOver = true; ?Zz'|.l@
//nPos = fileAccessI.write (b,0,nRead); [@"wd_f{l
} Owf.f;QR
catch(Exception e){e.printStackTrace ();} )1F<6R
} 'C?NJ~MN
} Qw)9r{f
}$gmK
M>l^%`
//打印回应的头信息 R,Oe$J<
public void logResponseHead(HttpURLConnection con) {6 .o=EyM{
{ \cuS>G
for(int i=1;;i++) x<B'.3y
{ Yrn"saVc,
String header=con.getHeaderFieldKey(i); Jx|I6y
if(header!=null) HIf{Z* mb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #^rU x.
Utility.log(header+" : "+con.getHeaderField(header)); [-w@.^:]X
else nr\q7
break; v{;7LXy0
} RL}KAGK
} HDIk9WC^
Z=+03
NZXjE$<Vr
public void splitterStop() Lz4ehWntO
{ Bw<rp-
bStop = true; Z1,gtl ?
} . (`3JQ2s
lCb+{OB
y79qwM.
} c-CYdi@
KN[d!}W:
6C-YyI#s#
/* >HTbegi
**FileAccess.java w+AuMc
*//文件访问(定位，写) dpzw.Z
package NetFox; ;IZ?19Q
import java.io.*; g]$ 4~"|.
+,flE=5]s
k#)Ad*t
public class FileAccessI implements Serializable{ t})$lM
(f1M'w/OD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q<{NO/Mm
RandomAccessFile oSavedFile; +=3CL2{An
long nPos; g-)mav
cT'w=
fCUT[d+H
public FileAccessI() throws IOException [Ot,q/hBJ
{ 3]LN;s]ac
this("",0); B)=~8wsI:Z
} ($!KzxF3
rVryt<2:@r
e!x6bR9EZ
public FileAccessI(String sName,long nPos) throws IOException {aj/HFLNY
{ %c/^_.
oSavedFile = new RandomAccessFile(sName,"rw"); %:u[MBe,
this.nPos = nPos; $Ua56Y
oSavedFile.seek(nPos); i|$z'HK;+
} t#~?{i@m
F@vbSFv)/
Cmd329AH
public synchronized int write(byte[] b,int nStart,int nLen) Rp.W,)i
{ eaZQ2
int n = -1; 7'w0
try{ Q/^A #l[
oSavedFile.write(b,nStart,nLen); sic$uT
n = nLen; N:BL=}V
} KSqTY>%fnv
catch(IOException e) | {P|.
{ F=wRkU
e.printStackTrace (); :Jxh2
} [aW=
|X(2Zv^O
~1(j&&kXet
return n; t/p $
} 1~5trsB+5
G$JFuz)|
oRY!\ADR
} IF_DZ
\7 a4uc
J)x3\[}Ye
/* c{3rl;Cs
**SiteInfoBean.java s:|M].
*/ y!Cc?$]_Y
package NetFox; ^^?q$1k6r*
_ Jc2&(;
<n0{7#PDqw
public class SiteInfoBean { hKe30#:v
T~>#2N-Z
%%}A|,
private String sSiteURL; //Site's URL ^gR+S
private String sFilePath; //Saved File's Path ]qktj=p
private String sFileName; //Saved File's Name l\Ftr_Dk
private int nSplitter; //Count of Splited Downloading File Wd 2sh
:d' 5O8
gRgog*z
public SiteInfoBean() Px;Cg 6
{//nSplitter的缺省值为5 ;st\I
//default value of nSplitter is 5 u?0d[mC
this("","","",5); ]> G&jd7
} igkz2SI
M7dU@Ag
z'MS#6|}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?b:_AO&
{ ?9KGnOVu
sSiteURL= sURL; *e4TSqC|
sFilePath = sPath; r/r:oXK
sFileName = sName; O!F]^'!
this.nSplitter = nSpiltter; *"9<TSU%m
_%pAlo_6
]T<^{jG
} Dn;p4T@
>P(`MSc
FjKq%.=#
public String getSSiteURL() 1:NS}r+>3.
{ - r#K#v3
return sSiteURL; :L$4*8@`+
} ujzW|HW^v
D3]BTkMMS;
HD-Erop
public void setSSiteURL(String value) XD%wj
{ 46XN3r
sSiteURL = value; Z85|I.mr
} La,QB3K/
<y=ovkM3
PZOKrW
public String getSFilePath() a(x?fa[D
{ "4 k-dj
return sFilePath; ?]!vRmZ;
} ^Kq|ID AP
^eh/HnJs
HnZPw&*
public void setSFilePath(String value) ^ddO&!U
{ !: us!s
sFilePath = value; 5K.+CO<
} m_lrPY-
Pl
b1^cD6sT+
public String getSFileName() RU_L<Lpi
{ T9jw X:n
return sFileName; TQ'E5^
} S@}4-\
*4yN3y
2$0)?ZC?=
public void setSFileName(String value) l5J.A@0
{ 8LrK94
sFileName = value; i0Pn Z J
} |B[eJq
v59nw]'
.W.;~`EW
public int getNSplitter() }~I|t!GL
{ |*\C{b
return nSplitter; '}{?AUDx
} 0HibY[_PbD
BQNp$]5s
`,#!C`E 9
public void setNSplitter(int nCount) uHvaZMu
{ bZ5n,KQA5
nSplitter = nCount; MCy~@)-IN
} 4rp6 C/i
} 2P}bG>M
U^$E'Q-VK
%z)EO9vtr
/* m|4LbWz
**Utility.java Tg''1 Wl*
*/ jnBC;I[:
package NetFox; 5~}!@yzc
nNR:cGfG
3M N
public class Utility { 8hB.fau
80&D""
"$)yB
public Utility() lB:l)!]||=
{ Y5%;p33uFG
}$aNOf%:
;`jU_
} e'~ Q@_D
(%DRt4u<H
//线程睡眠 =K'L|QKF
public static void sleep(int nSecond) s[V`e2O
{ <\DUo0]J
try{ GOr}/y;
Thread.sleep(nSecond); VGJDqm!
} _rjBc;a
catch(Exception e) %b<%w
{ Zi1YZxF`Y
e.printStackTrace (); AbY;H
} a4by^
} SIv[9G6
<}2A=~ _
//日志 5$^c@ 0
public static void log(String sMsg) X;]3$\F
{ }td6fj_{
System.err.println(sMsg); fsI`DjKi)
} .@K#U52
i./Y w
065A?KyD
public static void log(int sMsg) cx:jUsb6
{ rWe 8D/oc
System.err.println(sMsg); 9::YR;NY
} VjTAN=
} "1%*'B^}bw
cVg$dt
Q)dT(Td9~
/* %kW3hQ<$
**TestMethod.java ~UW{)]_jox
*/ Q9q9<J7j$
package NetFox; FB!z#Eim
va+m9R0
>fwlg-
public class TestMethod { /cY[at|p
h7RD`k:mF
P^;WB*V
public TestMethod() S41)l!+2
{ ///xx/weblogic60b2_win.exe f#c BQ~
try{ =U_@zDD@V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B>aEHb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !vrnoFVu
SiteFileFetch fileFetch = new SiteFileFetch(bean); VY{,x;O`
fileFetch.start(); nOr"K;C
} -;S3|
catch(Exception e){e.printStackTrace ();} F]SIT\kBm
c8\g"T
skSNzF7'
} |{!Ns+'
oHRbAE^
8fEAYRGd
public static void main(String[] args) c0hdLl;5
{ JrxP,[qJG
new TestMethod(); N$*>suQ,
} 4SBLu%=s%
} Qv=Bq{N
点击下载更多相关资料