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)); y.xt7 F1
} U9?fUS
for(int i=0;i<nEndPos.length-1;i++) |2i=oX(r|
{ +"sjkdum1
nEndPos = nStartPos[i+1]; .G ^-.p
} \a_75^2
nEndPos[nEndPos.length-1] = nFileLength; kIC$ai6.
} [uJfmrEH
} M2pe*z
(-<s[VnXP
l**gM
//启动子线程 w^AY= Fc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9.:]eL
for(int i=0;i<nStartPos.length;i++) fwkklg^
{ A"SF^p
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fbTq?4&Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qjcPJ
nStartPos,nEndPos,i); 6KvoHo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z[ NO`!<
fileSplitterFetch.start(); Q)/V>QW
} lQ8h-Tz
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^"\3dfzKM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <W>T!;4!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D]?eRO9'
nEndPos = " + nFileLength); @5["L
// fileSplitterFetch[nPos.length-1].start(); "jUM}@q5
z[cs/x
<:n!qQS6
//等待子线程结束 R&-Vm3mc3
//int count = 0; &x":
//是否结束while循环 ?Z0NHy;5
boolean breakWhile = false; \80W?9qj
r_x|2 AoO
~E8L,h~
while(!bStop) #JAy
{ eP?=tUB!S
write_nPos(); ir{li?kV
Utility.sleep(500); 5LF&C0v
breakWhile = true; bQvhBa?
D<QE?:#
<dD)>Y.
for(int i=0;i<nStartPos.length;i++) r6b;v2!8
{ cXd?48O
if(!fileSplitterFetch.bDownOver) ee}HQ.}Ja
{ ? PI2X.6
breakWhile = false; }fV+Kd$CB
break; fi,h`mdT?
} 8v ZY+Q >
} ; u@& [
if(breakWhile) t@;r~Sb
break; 5r)]o'?s
G%HuB5:u
R<)^--n
//count++; ( kKQs")
//if(count>4) ^.pd'
// siteStop(); +_T`tmQ
} lz [s
@2`$ XWD
!U"?vSl
System.err.println("文件下载结束！"); <k'%rz
} &)$}Nk
catch(Exception e){e.printStackTrace ();} vTl7x
} }T~}W8H
%K[u
X{u\|e{
//获得文件长度 -z~;f<+I`
public long getFileSize() c gOkm}h
{ \Q!I;
int nFileLength = -1; &cSZ?0R
try{ YApm)O={
URL url = new URL(siteInfoBean.getSSiteURL()); p.|M:C\xL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6Bf aB:
httpConnection.setRequestProperty("User-Agent","NetFox"); @OGHS}-\
rizWaw5E!8
k^#+Wma7
int responseCode=httpConnection.getResponseCode(); TY`t3
if(responseCode>=400) #/0d
{ i}gsxq%
processErrorCode(responseCode); [vTk*#Cl4
return -2; //-2 represent access is error $.F.xYS9IJ
} _]t^F9l
' 4.T1i,
a{@gzB
String sHeader; })yB2Q0
]99@Lf[^f
xl ]1TB@
for(int i=1;;i++) `LOW)|6r`
{ =mYwO=:D
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); O8k+R@
//Utility.log(in.readLine()); JFu9_=%+
sHeader=httpConnection.getHeaderFieldKey(i); _$P1N^}Zs
if(sHeader!=null) n09P!],Xa
{ rHp2I6.0a
if(sHeader.equals("Content-Length")) IAi|4,y_L
{ x K ;#C
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ~7>D>!!
break; LUzn7FZk
} c<ORmg6
} lSG]{
else a];1)zVA6
break; Ku?1QDhrF*
} ;~GBD]
} 1<;VD0XX
catch(IOException e){e.printStackTrace ();} i:|e#$x
catch(Exception e){e.printStackTrace ();} _>E=.$
2QgD<
oc"7|YG
Utility.log(nFileLength); \DcO.`L
FGzn|I
X@ S~D7|ja
return nFileLength; q.bxnta"
} $kBcnk
<~zPt&C]V
:n,x?bM
//保存下载信息（文件指针位置） M.67[Qj~"u
private void write_nPos() <-DQ(0xg
{ /s@j{*Om
try{ s+E: 7T9P
output = new DataOutputStream(new FileOutputStream(tmpFile)); bTMgEY
output.writeInt(nStartPos.length); 5KTPlqm0qF
for(int i=0;i<nStartPos.length;i++) .q<5OE(f
{ SQJ+C%
// output.writeLong(nPos); Mq='|0,
output.writeLong(fileSplitterFetch.nStartPos); (SMk!b]}
output.writeLong(fileSplitterFetch.nEndPos); srhI%Zj
} dVSQG947i:
output.close(); 9t!Agxm
} $;rvKco)%
catch(IOException e){e.printStackTrace ();} ?&=JGk^eJ
catch(Exception e){e.printStackTrace ();} "?^#+@LV
} M<r]a{Yv
Gkm{b[
*).!
//读取保存的下载信息（文件指针位置） 1&RB=7.h
private void read_nPos() 8@/MrEOW#
{ hi/Z>1ZOX
try{ B,] AfH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [Z^26/5a
int nCount = input.readInt(); Y+h ?HS
nStartPos = new long[nCount]; s Fx0
nEndPos = new long[nCount]; .hJcK/m
for(int i=0;i<nStartPos.length;i++) Dq-[b+bm
{ <cxe
nStartPos = input.readLong(); Zb&"W]HSf
nEndPos = input.readLong(); ZiPz~G0[^
} b&6lu4D
input.close(); rX0 ?m:&m
} B`YD>oCN
catch(IOException e){e.printStackTrace ();} 5,+fM6^V
catch(Exception e){e.printStackTrace ();} sR^b_/ElxT
} 4";NT;_q5
h]vEXWpG]
gvr&7=p
private void processErrorCode(int nErrorCode) xo4lM
{ y&/bp<Z
System.err.println("Error Code : " + nErrorCode); sN K^.0
} V.ETuS;
!<out4Mz"
kgI8PybY
//停止文件下载 kek/C`7
public void siteStop() T\#Gc4
{ SLNq%7apx
bStop = true; Sk-Q 4D^
for(int i=0;i<nStartPos.length;i++) Lyz8DwZ
fileSplitterFetch.splitterStop(); U'u_'5{
~NB|BwAh
CM7NdK?I
} \58bz<u"
} U "r)C;5
//负责部分文件的抓取 ;NQ}c"9
**FileSplitterFetch.java ky&wv+7
*/ N 'n0I^Y1A
package NetFox; u}P:9u&h6X
BLAF{vVaf
my/KsB
import java.io.*; FzykC
import java.net.*; QNXoAx%I
_.E{>IFw
AxeQv'e
public class FileSplitterFetch extends Thread { 6"NtVfui
X(BX+)YR
M!i*DU+SE
String sURL; //File URL *sau['Ha
long nStartPos; //File Snippet Start Position fg lN_
long nEndPos; //File Snippet End Position 2%pU'D:
int nThreadID; //Thread's ID _BONN6=*y
boolean bDownOver = false; //Downing is over e*}:tH
boolean bStop = false; //Stop identical ysPm4am$
FileAccessI fileAccessI = null; //File Access interface l*{Bz5hc
HCCq9us
/ !y~Q|<|=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6=Wevb5YJ
{ (P=WKZMPN
this.sURL = sURL; zg'.fUZ
this.nStartPos = nStart; [#YzU^^Ib
this.nEndPos = nEnd; e"*1l>g
nThreadID = id; $:# :"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |KZX_4
} uF1&m5^W
L8H:,} 2
X&h?1lMJ /
public void run() Mlr'h}:H
{ ~d3@x\I?
while(nStartPos < nEndPos && !bStop) 3ZI:EZ5
{ oRJ!TAbD
nLmF5.&
J"@X>n
try{ Ux{0)"fj
URL url = new URL(sURL); ZJ~0o2xZ'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jt#HbAY
httpConnection.setRequestProperty("User-Agent","NetFox"); ?3qp?ea
String sProperty = "bytes="+nStartPos+"-"; X y`2ux+>/
httpConnection.setRequestProperty("RANGE",sProperty); hW9!
Utility.log(sProperty); KeB??1S
/9,'.
.'$8Hj;@
InputStream input = httpConnection.getInputStream(); '9zKaL
//logResponseHead(httpConnection); dG8mE&$g
c5uC?b].
6k![v@2R
byte[] b = new byte[1024]; xB[W8gQ6fa
int nRead; GmE`YW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) H "5,To
{ E:k]Z
nStartPos += fileAccessI.write(b,0,nRead); e igVT4
//if(nThreadID == 1) ^*+M9e9Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z@o6[g/*Q
} (C1~>7L
CE!cZZ
>,tJq%
Utility.log("Thread " + nThreadID + " is over!"); bfEH>pQ>#
bDownOver = true; xK)<763q>
//nPos = fileAccessI.write (b,0,nRead); 2y|n!p T
} ]~VuY:abH
catch(Exception e){e.printStackTrace ();} -QR]BD%J*[
} Qx3eEt@X5]
} ]=ZPSLuEm%
'h7x@[|
if*~cPnN
//打印回应的头信息 aMxj{*v7
public void logResponseHead(HttpURLConnection con) $tXW/
{ l_$>$d
for(int i=1;;i++) 2{Dnfl'k
{ <#;5)!gr{
String header=con.getHeaderFieldKey(i); Mk=*2=d
if(header!=null) h-sO7M0E]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !syyOfu`}
Utility.log(header+" : "+con.getHeaderField(header)); fAz4>_4
else :VWN/m
break; |(TEG.<g
} Y2'HP)tfIw
} WNb2"W
\x:U`T
\IYv9ScAx
public void splitterStop() 6rWq hIaI
{ R,["w98a
bStop = true; \ltS~EuWU
} xLLTp7b(
'p\&Mc_Gu
Cg%Owe/E?0
} ki}Li*)7
!.MbPPNp
a&2x;diF
/* EYZ&%.Sy5
**FileAccess.java OwPHp&{ Y
*//文件访问(定位，写) lZe-A/E
package NetFox; ujN~l_4
import java.io.*; 9n\v{k=
[5M!'
7<2?NLE8*
public class FileAccessI implements Serializable{ yd45y}uS;F
U}=H1f,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %\B?X;(
RandomAccessFile oSavedFile; 6/(Z*L"~6k
long nPos; <3=k
JE$$6X
]i `~J
public FileAccessI() throws IOException ,s@S`KS0
{ 91T[@p
this("",0); eR3MU]zF
} +K;%sAZy
b+CvA(*
gKPqU@$*
public FileAccessI(String sName,long nPos) throws IOException Zyz)`>cB
{ [E}pU8.t6
oSavedFile = new RandomAccessFile(sName,"rw"); Nk F2'Z{$+
this.nPos = nPos; RcI0n"Gi_
oSavedFile.seek(nPos); !+Sd%2o
} ry* 9
q'biTn]2
1gYvp9Ma
public synchronized int write(byte[] b,int nStart,int nLen) tf9a- s
{ IueI7A
int n = -1; i.ivHV~-
try{ X%B2xQM5
oSavedFile.write(b,nStart,nLen); A2fuNV_
n = nLen; kh>i#9Ie
} oT}Sh4Wt.
catch(IOException e) GMob&0l8_
{ gGbqXG^
e.printStackTrace (); uv7tbI"r
} &v+Hl^
>LEp EMJ\
h&bs`
return n; *AYjMCo
} ]jP0Z#
)VxC v
-9"[/
} (G{2ec:?
HR?a93
0:>C v<N
/* o7:"Sl2AD
**SiteInfoBean.java .[o?qCsw
*/ O'W[/\A56M
package NetFox; sRGIHT#
!f8]gTzN
|\q@XCGei
public class SiteInfoBean { =$vy_UN
|DoD.?v
T7XbbU
private String sSiteURL; //Site's URL Oj.xJ(uX+v
private String sFilePath; //Saved File's Path YoRD9M~iG~
private String sFileName; //Saved File's Name ot,e?lF
private int nSplitter; //Count of Splited Downloading File aw'o=/a8
0kld77tn 2
#TY[\$BHs
public SiteInfoBean() Jd/XEs?<q
{//nSplitter的缺省值为5 1`EkN0iZ
//default value of nSplitter is 5 @)Sd3xw[
this("","","",5); DUu~s,A
} @?<1~/sfL
>`.$Tyw
VWE`wan<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hc5iIJ]
{ ^Jn=a9Q6Z
sSiteURL= sURL; -D,kL
sFilePath = sPath; 9TOqA4
sFileName = sName; &GLe4zEh
this.nSplitter = nSpiltter; u69s}yZ
5JRj'G0I
\"hP*DJ"
} eWAgYe2
23[XmBf
5_Opx=
public String getSSiteURL() m^ [VM&%
{ M/a5o|>8
return sSiteURL; BpZ17"\z
} .2:S0=xt<
S.A|(?x
]k.'~Syz
public void setSSiteURL(String value) D<XRu4^;
{ 2*@.hBi
sSiteURL = value; AwO'%+Bv
} 7`Bwo*Y
[}bPkD
G .k\N(l
public String getSFilePath() DANndXQLH
{ YO^iEI.
return sFilePath; /QCyA%y
} >^hy@m
Di8;Tq
[xsiSt?6
public void setSFilePath(String value) 9J'3b <
{ O/2Jz
sFilePath = value; J?N9*ap)
} ;Q} H'Wg,
f.y~Sew
5uufpvah
public String getSFileName() 0ge^pO\Z
{ Ffp<|2T2_
return sFileName; Rk.GrLp
} !4l\*L
IB+)2`
bP,_H
public void setSFileName(String value) [r5k8TB1
{ *=ymK*
sFileName = value; z7P]g C$\
} &,B91H*#
#XlE_XD
d~b#dcv$"
public int getNSplitter() CAD:ifV
{ *PVv=SU
return nSplitter; SMdkD]{g
} XUyoZl?
t,yzqn
eZWR)+aq
public void setNSplitter(int nCount) 2dF:;k k
{ WrGz`
nSplitter = nCount; eL+L {Ac
} HKdR?HM1
} @GiR~bKZ
PNbs7f
.{|AHW&0<
/* >xt*(j&}
**Utility.java fii\&p7z
*/ `(9B(&t^,
package NetFox; :tA|g
Uieg4Iro
.ZxH#l _
public class Utility { a;A&>Ei}
*0^t;A+
|UO1vA@
public Utility() U "qO&;m
{ H5N(MihT
X&<#3n
d.7Xvx0Yww
} adJoT-8P6
Lu~e^Ul
//线程睡眠 +(3PY e\
public static void sleep(int nSecond) Ik#>6
{ IP1|$b}sq
try{ Kup-O u,
Thread.sleep(nSecond); vR?L/G^.
} ^/Hj^4~_U
catch(Exception e) DOXRU5uP3
{ g"3h#SMb
e.printStackTrace (); ;D/'7f7.}
} #oYX0wvl
} Oh:SH|=]#
RU`TzD
//日志 K@{jY\AZNx
public static void log(String sMsg) T T0O %
{ rr4yJ;qpeP
System.err.println(sMsg); XEZ6%Q_
} tS2lex%
?<w +{
@D"1}CW
public static void log(int sMsg) nX Qz
{ #%e`OA(b
System.err.println(sMsg); /]xd[^
} Yb =8\<;
} UsQv!Cwu^
RpLm'~N'
yB.6U56
/* ==(M vu`
**TestMethod.java l}AB):<Z
*/ Gz*U?R-T
package NetFox; <6apv(2a
$i`YtV
n_+Iw,a'm
public class TestMethod { 3~S~)quwP
0!zWXKX
_6[NYv$"
public TestMethod() C'$U1%: j
{ ///xx/weblogic60b2_win.exe CRf^6k_;(
try{ {M$8V~8D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #\M<6n{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~\_E%NR yA
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9(I4x]`
fileFetch.start(); [gE2lfaEy
} oy |@m|J
catch(Exception e){e.printStackTrace ();} NSkI2>+P
P6?Q;-\q0
w])Sz*J
} 2-6-kS)c
&,)tD62s
:H87x?e[
public static void main(String[] args) :=8vy
{ cP Y^Bf5)
new TestMethod(); v;A
} f;Dz(~hw
} XU54skN
点击下载更多相关资料