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)); 8~ .r/!wfy
} >sm< < gVb
for(int i=0;i<nEndPos.length-1;i++) A{: a kK
{ Z=z'j8z3
nEndPos = nStartPos[i+1]; |08tQ
} QVL92"
nEndPos[nEndPos.length-1] = nFileLength; :o*{.
} Fb*^GH)J
} UB|Nx(V s
HO41)m+&
"6Nma)8
//启动子线程 "@ Zy+zLU
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }pu2/44=W
for(int i=0;i<nStartPos.length;i++) 4Yt:PN2
{ F04`MY"
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j{7_p$JM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W6K]jIQ
nStartPos,nEndPos,i); KOV^wSwS
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q_g'4VZv
fileSplitterFetch.start(); 5f=e JDo=x
} _Jj|g9b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -F4CHpua
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z]1~9:7ap
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rMTtPuc2
nEndPos = " + nFileLength); Cl\Vk
// fileSplitterFetch[nPos.length-1].start(); -tF5$pb'
#`:60#l
\'GX^0yK
//等待子线程结束 Al$"k[-Uin
//int count = 0; x,2+9CCU
//是否结束while循环 {p9y{$
boolean breakWhile = false; #8R\J[9
> 9JzYI^
jXGr{n
while(!bStop) BpDf4)|
{ yh]#V"W3
write_nPos(); X3!btxa%t
Utility.sleep(500); bRLmJt98P
breakWhile = true; lR{eO~'~V
#|A @
Y%^&aacZ
for(int i=0;i<nStartPos.length;i++) =5oFutg`
{ JXftQOn
if(!fileSplitterFetch.bDownOver) ah"2^x
{ EqUiC*u8{I
breakWhile = false; :QUZ7^u
break; Dd!MG'%hlb
} H6/@loO!Xy
} hNyYk(t^
if(breakWhile) @xtcjB9
break; L G,XhN
=Q.2:*d.
A8e b{qv
//count++; WyA>OB<Zeq
//if(count>4) za<Ja=f9X
// siteStop(); zXbTpm
} vo!:uvy;2
dB<BEe\$g.
+;Q&
System.err.println("文件下载结束！"); ^(N+s?
} "0`r]5 5d
catch(Exception e){e.printStackTrace ();} k1$|vzMh
} <Sm=,Sw
k:m~'r8z
k#JFDw\
//获得文件长度 s]5wzbFO
public long getFileSize() WT'P[RU2
{ ,BW^j.7
int nFileLength = -1; 7xwS .|
try{ BG-uKJ ^
URL url = new URL(siteInfoBean.getSSiteURL()); =H>rX 2k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #MHnJ
httpConnection.setRequestProperty("User-Agent","NetFox"); #n{wK+lz
_AI2\e
7Q0M3m
int responseCode=httpConnection.getResponseCode(); Q7"KgqpQ3
if(responseCode>=400) ~bigaY
{ .oaW#f}0P
processErrorCode(responseCode); miZ{V%
return -2; //-2 represent access is error A. U<
} ]pB0bJAt
q jDWA'
(66X
String sHeader; gLl?e8[F
pF K[b
z+PSx'#}
for(int i=1;;i++) _f|Au`7m
{ DcSL f4A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]'~'V2Ey
//Utility.log(in.readLine()); 1^!=J<`K;
sHeader=httpConnection.getHeaderFieldKey(i); o%M~Q<wf
if(sHeader!=null) baR{
{ %+gze|J
if(sHeader.equals("Content-Length")) {'"A hiR/
{ KOhy)h+ h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fa\<![8LAU
break; 6\4oHRJC
} >^|\wy
} /y@$|DI1
else B(Y{
break; ^=OjsN
} t Z\
} f:Nfw+/q
catch(IOException e){e.printStackTrace ();} F mh;d*IT
catch(Exception e){e.printStackTrace ();} w,eYrxR|N
[ueT]%
75!IzJG
Utility.log(nFileLength); &m>`+uVBP
CyzvQfpZr
*r:8=^C7S
return nFileLength; 3c@Cb`w@
} kL*Q})
S;+bQ.
%3fHitCikc
//保存下载信息（文件指针位置） 9m!4U2N,s
private void write_nPos() `9a%}PVQ-
{ [p}J=1S
try{ =<`9T_S 16
output = new DataOutputStream(new FileOutputStream(tmpFile)); dMeDQ`c`W
output.writeInt(nStartPos.length); */nb%QV
for(int i=0;i<nStartPos.length;i++) \ts:'
{ G{+sC2
// output.writeLong(nPos); =zqOkC h$
output.writeLong(fileSplitterFetch.nStartPos); PS`)6yn{_
output.writeLong(fileSplitterFetch.nEndPos); ?h1]s&^|2
} hP3I_I[qF}
output.close(); 5{,/m"-
} zhHQJcQ.
catch(IOException e){e.printStackTrace ();} Z(/jQ=ozQ
catch(Exception e){e.printStackTrace ();} vB/MnEKR
} ua`2 &;T=
e{To&gy~
E^A9u |x
//读取保存的下载信息（文件指针位置） +c}fDrr)
private void read_nPos() T>vHZZiO
{ Nf-IDK
try{ 9y.C])(2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C<qJnB:B9
int nCount = input.readInt(); h(GgkTj4+
nStartPos = new long[nCount]; "*%=k%'
nEndPos = new long[nCount]; cQ*:U@
for(int i=0;i<nStartPos.length;i++) oIoJBn
{ Iimz
nStartPos = input.readLong(); f*W<N06EZ
nEndPos = input.readLong(); (d4zNYK
} ,8+SQo#3
input.close(); +P}'2tE~'
} "LP4)hr_`
catch(IOException e){e.printStackTrace ();} q/70fR7{v
catch(Exception e){e.printStackTrace ();} j#-ZL-N
} -a&wOn-W
<gf:QX!
2NIK0%6
private void processErrorCode(int nErrorCode) ;oob TW{
{ saU|.\l
System.err.println("Error Code : " + nErrorCode); H'?Bx>X
} -("79v>#
Pa0tf:
jY87NHg
//停止文件下载 1ww|km
public void siteStop() &vdGKYs 6
{ p7zHP
bStop = true; :Gy .P
for(int i=0;i<nStartPos.length;i++) @iC!Q>D
fileSplitterFetch.splitterStop(); J>!p^|S{
)bi*y`UM]
@hl5^d"l
} N<"_5
} c)iQ3_&=
//负责部分文件的抓取 >hB]T%'
**FileSplitterFetch.java YCw^u
*/ MZv&$KG4m@
package NetFox; t8]u#bx"?
oo-^BG
cO)GiWE
import java.io.*; ?o9l{4~g
import java.net.*; _f^q!tP&d
=Q3Go8b4HJ
r;upJbSX
public class FileSplitterFetch extends Thread { o=;.RYi
ik7#Og~3
L_)?5IOJ$
String sURL; //File URL 5!tmG- 'b
long nStartPos; //File Snippet Start Position N4)&K[
long nEndPos; //File Snippet End Position YA{Kgc^
int nThreadID; //Thread's ID [OH>NpL
boolean bDownOver = false; //Downing is over T_v
boolean bStop = false; //Stop identical ou,W|<%
FileAccessI fileAccessI = null; //File Access interface W=I%3F_C"R
oUltr
:T%,.sH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n9cWvy&f
{ -}4H'%Z(i
this.sURL = sURL; Yk?uxZ4)H
this.nStartPos = nStart; LO#{
this.nEndPos = nEnd; mUcHsCszH
nThreadID = id; c7wza/r>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4zJ9bF4
} "/ @ ;6
KC q3S
(873:"(
public void run() IK~ur\3
{ C[gSiL
while(nStartPos < nEndPos && !bStop) YJrK oK}
{ 8'`&f&
Vk0O^o
cf0em!
try{ FCqs'
URL url = new URL(sURL); 7F}I.,<W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <C${1FO7If
httpConnection.setRequestProperty("User-Agent","NetFox"); -cY/M~
String sProperty = "bytes="+nStartPos+"-"; 'Nfg%)-N
httpConnection.setRequestProperty("RANGE",sProperty); 1D=My1B
Utility.log(sProperty); GbB&kE3KP
6kIq6rWF9
t MA
InputStream input = httpConnection.getInputStream(); ,,fLK1
//logResponseHead(httpConnection); Rg0\Ng4|G
2S!=2u+7
e|+uLbN&;c
byte[] b = new byte[1024]; -bo0!@MK
int nRead; d=lZhqY
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^B1vvb
{ {nj\dU
nStartPos += fileAccessI.write(b,0,nRead); 8 hWQ
//if(nThreadID == 1) A4(^I u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %\:.rs^
} = 2My-%i
p)TH^87
`pII-dSC%
Utility.log("Thread " + nThreadID + " is over!"); prIq9U|@
bDownOver = true; *2;w;(-s
//nPos = fileAccessI.write (b,0,nRead); ]S;e#u{QE
} f)"O( c
catch(Exception e){e.printStackTrace ();} e[Q(OV5(R
} ^+,mxV'8!
} #i)h0ML/e
H(?z?2b p
u@==Ut
//打印回应的头信息 'e{e>>03
public void logResponseHead(HttpURLConnection con) VMen:
{ +k8><_vr}
for(int i=1;;i++) NbkWy
{ |$bZO`^
String header=con.getHeaderFieldKey(i); |6_<4lmTxF
if(header!=null) pjbKMx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H3`%#wQ0j
Utility.log(header+" : "+con.getHeaderField(header)); L6l~!bEc
else m#%5H
break; "#[Y[t\Ia
} x`C;
} k`\DC\0RG
CgEeO,N]j
7p u*/W~
public void splitterStop() FUq@ dUv
{ {&K#~[)
bStop = true; [Hn+r&
} I&>R]DV
Vfc9+T+
{d^&$~
} %v}:#_va]
.HGEddcC
0B3*\ H}5
/* $9Z8P_^.0(
**FileAccess.java eDTEy;^o
*//文件访问(定位，写) eZP"M6
package NetFox; EkXns%][L
import java.io.*; "%>/rh2Iq
(VBoZP=W
7F+w o
public class FileAccessI implements Serializable{ o`G'E&
{#Gr=iv~N
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 LX*T<|c`'
RandomAccessFile oSavedFile; `"-)ObOj}
long nPos; OmKT}D~ 4
z KJ6j]m
&a48DCZ
public FileAccessI() throws IOException rBgLj,/`U/
{ o @&#*3<_e
this("",0); *h-nI=
} W.0dGUi*
VQqEsnkz
UN,@K9
public FileAccessI(String sName,long nPos) throws IOException -Frx{3
{ G]q6Ika
oSavedFile = new RandomAccessFile(sName,"rw"); ~>#=$#V
this.nPos = nPos; ,Sz*]X
oSavedFile.seek(nPos); /H!I90
} M-|4cd]6
NGS/lKz
%)q5hB
public synchronized int write(byte[] b,int nStart,int nLen) b/O~f8t
{ eJJvEvZ,
int n = -1; }tj@*n_
try{ a*%>H(x
oSavedFile.write(b,nStart,nLen); Ce`{M&NSWX
n = nLen; hnG'L*HooE
} Z;??j+`Eo
catch(IOException e) :LcR<>LZ
{ s "*Cb*
e.printStackTrace (); <VgnrqF6:
} ze,HNFg@>
:X2B+}6_&
c&F"tLl
return n; >@y5R^B`
} >`s2s@Mx
PiAA,
p^~lQ8t
} O`|'2x{[O
#^Sd r-
Fwho.R-.
/* HjV83S;
**SiteInfoBean.java Q[8L='E
*/ n*bbmG1
package NetFox; KvktC|~?
GH^i,88
PTL52+}/
public class SiteInfoBean { :5h&f
l'-iIbKX
ogjm6;
private String sSiteURL; //Site's URL H={fY:%
private String sFilePath; //Saved File's Path \JN<"/
private String sFileName; //Saved File's Name ,bJZs-P0
private int nSplitter; //Count of Splited Downloading File R.>/%o
"C}nS=]8m
::adT=
public SiteInfoBean() 2eb :(D7Cq
{//nSplitter的缺省值为5 [ &R-YQ@
//default value of nSplitter is 5 t{84ioJ"$
this("","","",5); hDVD@b
} <\Y>y+$3
Y@#~8\_
eMWY[f3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mn 8A%6W
{ "L{;=-e
sSiteURL= sURL; oPre$YT}h
sFilePath = sPath; $@Hw DRP
sFileName = sName; p?8>9
this.nSplitter = nSpiltter; m,*t}j0 7
1Pn!{ bU3@
;~/
} o+6Y/6Xp@
1VJE+3
,n&Dg58K
public String getSSiteURL() 6OIA>%{
{ 7jEAhi!Cq(
return sSiteURL; Z@~8iAgE
} W&Fa8
<8jn_6
"$ u"Py
public void setSSiteURL(String value) nQ/(*d
{ 8!:4m"Y
sSiteURL = value; ilzR/DJMa
} B;?a. 81~
$,'r} %
7xWX:2l*?
public String getSFilePath() #4~Ivj
{ HM ^rk
return sFilePath; i-tX5Md|
} q]'VVlP)
w3,QT}WvY
%;ny
public void setSFilePath(String value) +Uj~zx@
{ #(XP=PUj
sFilePath = value; ?i9LqHL
} g($y4~#
]9b*!n<z
5r`g6@
public String getSFileName() Pm" ,7
{ :5C9uW#
return sFileName; xr.fZMOh4
} kO/dZ%vj
=Z%&jul
97<Y. 0
public void setSFileName(String value) b"{7f
{ 1gCp/m2r7
sFileName = value; Fvi<5v
} qRB&R$
vgsu~(L;
5b|_?Em7
public int getNSplitter() >/evL /
{ hM+nA::w
return nSplitter; 5RZAs63t
} ?XW+&!ar
i[WTp??Uv
[Zgy,j\\
public void setNSplitter(int nCount) =C5[75z#+
{ \XmtSfFC
nSplitter = nCount; l3(k
} zBqr15
} DF9Br D0{
ygT,I+7\
.KK"KO5k
/* rpy`Wz/[
**Utility.java I"Y?vj9]
*/ ?Yz.tg
package NetFox; :'.-*Ew
`(Ei-$ >U&
$]Y' [pE@
public class Utility { +h*&r~T
pOw4H67
wBCnP
public Utility() 1AA(qE
{ Auv/w}zrr
<}.)kg${O
^3AJYu
} %Sxy!gGz%%
C,jPr )6)
//线程睡眠 o3}12i S
public static void sleep(int nSecond) yTbBYx9Bi
{ VJuPC
try{ `4l>%S8y:
Thread.sleep(nSecond); ]FQ4v.7
} /sJk[5!z
catch(Exception e) QDxLy aL
{ G{ F>=z"(l
e.printStackTrace (); m0/J3
} s7df<dBC
} qY#*zx
h_y<A@[P}
//日志 (}]74Lc
public static void log(String sMsg) $+*ZsIo
{ Tz%l9aC
System.err.println(sMsg); -YSn 3=
} (;Lz`r'
QZQ@C#PR;
@{t^8I#]
public static void log(int sMsg) F fl`;M
{ <*4=sX@
System.err.println(sMsg); M(oW;^B
} y]cx}9~
} t"RgEH@
MY1 tYO
dbnH#0i
/* 0Dh a1[=
**TestMethod.java $Q]`+:g*}
*/ t*Lo;]P
package NetFox; <&W3\/xx
X,T^(p
`EWeJ(4Z@
public class TestMethod { XXe7w3x{
h1)p{5}H
)t)tk=R9N
public TestMethod() HjnHl-
{ ///xx/weblogic60b2_win.exe zU1rjhv+
try{ YXD1B`23
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T5Pc2R
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 5O)Z}
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~{+J~5!;<H
fileFetch.start(); #1m!,tC
} 1d-j_H`s
catch(Exception e){e.printStackTrace ();} [C7:Yg7
RZ?>>Ll6
paMw88*u
} QKHmOVh]
Prjl ;[I}
sU+~#K$b
public static void main(String[] args) XV+BSW7}
{ >E)UmO{S
new TestMethod(); GI6 EZ}.MZ
} p4aM`PW8>=
} v SWqOv$
点击下载更多相关资料