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)); Ct"h.rD]
} L>pP3[~DV
for(int i=0;i<nEndPos.length-1;i++) ;~/
{ o+6Y/6Xp@
nEndPos = nStartPos[i+1]; 1VJE+3
} ,n&Dg58K
nEndPos[nEndPos.length-1] = nFileLength; B.{0,bW?
} .hT^7|Jz[
} WY<ip<
OEZXV ;F
<}i\fJX6
//启动子线程 ng<|lsZd
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; gEPCXf
for(int i=0;i<nStartPos.length;i++) uOm fpgO
{ c;(}Ih(#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;k!Ej-(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rQ~%SUM7
nStartPos,nEndPos,i); 63F0Za}h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SM0=
fileSplitterFetch.start(); uQpV1o5iA
} bjD0y cB[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Xo]FOJ5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); d{9jd{ _#G
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6,cyi|s
nEndPos = " + nFileLength); s g6
// fileSplitterFetch[nPos.length-1].start(); S{fNeK
c3K(mM:
:@YZ6?hf
//等待子线程结束 ?WUu@Z
//int count = 0; ]lm9D@HMC
//是否结束while循环 z2nDD6N
boolean breakWhile = false; ?i9LqHL
zb:p,T@5
g($y4~#
while(!bStop) N2q'$o
{ ~-'nEATE
write_nPos(); MPM_/dn-
Utility.sleep(500); UW)k]@L
breakWhile = true; |A5]hL
gqGl>=.m
9)mJo(
for(int i=0;i<nStartPos.length;i++) ,4EE9 ?J
{ 5TzMv3;in2
if(!fileSplitterFetch.bDownOver) kO/dZ%vj
{ Av+R~&h
breakWhile = false; ~~wz05oRG
break; Z(.p=Wg
} mxDy!:@=
} *3. ]
if(breakWhile) mlIc`GSI
break; =`.9V<
&({X9
ihs@ 'jh
//count++; 6VCw>x
//if(count>4) C 5)G^
// siteStop(); o5AyJuS-u$
} W}JJaZR*X
njvmf*A?S
vW YN?"d
System.err.println("文件下载结束！"); wGb{O
} +F4xCz7f
catch(Exception e){e.printStackTrace ();} 9SMM%(3, r
} u3ce\
Etn]e;z4
!K6:W1
//获得文件长度 W99Fb+$I
public long getFileSize() c69B[Vjb
{ [Zgy,j\\
int nFileLength = -1; j3A+:KDn3n
try{ Rp9uUJ 6o
URL url = new URL(siteInfoBean.getSSiteURL()); k6G23p[9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KHdj#3<AR
httpConnection.setRequestProperty("User-Agent","NetFox"); 8Ck:c45v
-OVJ]
}7Pd\tG]
int responseCode=httpConnection.getResponseCode(); (3=.3[
if(responseCode>=400) JWH}0+1*
{ WYI? M
processErrorCode(responseCode); NoiU5pP
return -2; //-2 represent access is error TC J\@|yw
} ,!bOzth2>K
vC+mC4~/(
`(Ei-$ >U&
String sHeader; *4=Fy:R]O
\/{qE hP
S.M< (
for(int i=1;;i++) jZ.+b j >
{ (Z6[a{}1i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x$6-7<p
//Utility.log(in.readLine()); X9zTz2 Fy
sHeader=httpConnection.getHeaderFieldKey(i); >8jDW "Ua
if(sHeader!=null) CbK7="48
{ /WMG)#kw'
if(sHeader.equals("Content-Length")) F'|,(P
{ ^3AJYu
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); -/7[_,
break; Tcr&{S&o
} j+Wgjf
} %xWmzdn
else .{)b^gE
break; Z&J417buk
} yTbBYx9Bi
} ZL~}B.nqS
catch(IOException e){e.printStackTrace ();} bNIT 1'v
catch(Exception e){e.printStackTrace ();} p4(-
p72+:I
E/AM<eN
Utility.log(nFileLength); }{E//o:Ta
"ve?7&G7U
-7;RPHJs
return nFileLength; rPr#V1}1a
} rA{h/T"
_czLKbcF
4#4kfGoT
//保存下载信息（文件指针位置） OM2|c}]ZQ
private void write_nPos() uyAhN
{ ;#f_e;
try{ j:U>V7Kn3~
output = new DataOutputStream(new FileOutputStream(tmpFile)); z,/dYvT<
output.writeInt(nStartPos.length); 6o6!Ol
for(int i=0;i<nStartPos.length;i++) h-!(O^M
{ eYR/kZ%<
// output.writeLong(nPos); C:gE
output.writeLong(fileSplitterFetch.nStartPos); 5p"*nkF
output.writeLong(fileSplitterFetch.nEndPos); 0nhsjN}v
} -YSn 3=
output.close(); z36nyo
} GpxGDN3?
catch(IOException e){e.printStackTrace ();} L{ .r8wSrI
catch(Exception e){e.printStackTrace ();} BWw7o{d
} |%zhwDQ.
lWnV{/q\X
qWQJ>
//读取保存的下载信息（文件指针位置） xZ4\.K\f]
private void read_nPos() w)DO"Z7
{ V<ODt%
try{ o{>hOs &
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5)&e2V',y
int nCount = input.readInt(); vP&*(WfO)
nStartPos = new long[nCount]; X(Ef=:
nEndPos = new long[nCount]; MY1 tYO
for(int i=0;i<nStartPos.length;i++) u'?t'I
{ &QCqaJ-
nStartPos = input.readLong(); S,Tm=} wj
nEndPos = input.readLong(); I|iI ,l/9
} 15nc
input.close(); `Gsh<.w!7
} t*Lo;]P
catch(IOException e){e.printStackTrace ();} 9n@jK%m
catch(Exception e){e.printStackTrace ();} P`U5kNN
} Xb|hP
X,T^(p
@LwhQ
private void processErrorCode(int nErrorCode) hhYo9jTHW
{ |a^ydwb
System.err.println("Error Code : " + nErrorCode); 7W}~c/%
} ,0#OA*0B
1F[; )@
nJ2l$J<
//停止文件下载 UP,0`fh(y
public void siteStop() T_YN^za(q
{ azOp53zR
bStop = true; Q5ohaxjF
for(int i=0;i<nStartPos.length;i++) wiwJD}3h'
fileSplitterFetch.splitterStop(); j|+B|
|#!25qAT
G-,PsXSwe
} e(!a~{(kq%
} mHw1n=B
//负责部分文件的抓取 ^Ko0zz|R/
**FileSplitterFetch.java [C7:Yg7
*/ .fQDj{
package NetFox; @X4;fd
Za=<euc7
:Z1_;`>CT
import java.io.*; QKHmOVh]
import java.net.*; rZ0@GA
o"'VI4
)%#hpP M^
public class FileSplitterFetch extends Thread { A3 j>R477A
5{cAawU.
i<=@7W
String sURL; //File URL _L# Tp
long nStartPos; //File Snippet Start Position Blaj07K
long nEndPos; //File Snippet End Position gdkO|x
int nThreadID; //Thread's ID hA/FK
boolean bDownOver = false; //Downing is over 5!y3=.j
boolean bStop = false; //Stop identical W>1\f0'
FileAccessI fileAccessI = null; //File Access interface LJI&j \
?:H9xJ_^
sH+]lTSX6{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .:<c[EJ b
{ dcXtT3,kpX
this.sURL = sURL; JziMjR
this.nStartPos = nStart; 6 t A?<S
this.nEndPos = nEnd; QW~o+N~~
nThreadID = id; p8F|]6Z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4I,@aj46
} Txp~&a03
_VY]
%/S BJ
public void run() Zz/w>kAG*{
{ N<:Ra~Ay
while(nStartPos < nEndPos && !bStop) &;%+Hduc
{ 1b_->_9
z|pH>R?:
Dw.>4bA.
try{ B5tJ|3!
URL url = new URL(sURL); ,ew<T{PL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ",~3&wx
httpConnection.setRequestProperty("User-Agent","NetFox"); EE%OD~u&9#
String sProperty = "bytes="+nStartPos+"-"; IP{Cj=
httpConnection.setRequestProperty("RANGE",sProperty); 3&2,[G04
Utility.log(sProperty); U][.ioc
V(w[`^I>~
^P{'l^CVX
InputStream input = httpConnection.getInputStream(); *23
//logResponseHead(httpConnection); q)@.f.
R` X$@iM
EDnmYaa)dZ
byte[] b = new byte[1024]; !)LR41>?
int nRead; zb;2xTH+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;q$<]X_S)}
{ 6] <?+#uQ
nStartPos += fileAccessI.write(b,0,nRead); J'B;
//if(nThreadID == 1) >6<g5ps.n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J^t=.-a|
} ^g~-$t<!
e=2;z
Ulktd^A\
Utility.log("Thread " + nThreadID + " is over!"); 75^-93
bDownOver = true; jhg!K.A
//nPos = fileAccessI.write (b,0,nRead); mZq*o<kTA
} =8tduB
catch(Exception e){e.printStackTrace ();} W^yF5
} L`"cu.l
} OgOu$.
t^h>~o'\
VfZ/SByh7p
//打印回应的头信息 2\s-4H| q
public void logResponseHead(HttpURLConnection con) yn%w'
{ co~TQpy^
for(int i=1;;i++) <(^-o4Cl
{ )hQ`l d7B
String header=con.getHeaderFieldKey(i); ]%mg(&p4
if(header!=null) YY]LK%-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i]1[eGF
Utility.log(header+" : "+con.getHeaderField(header)); )<3WVvB
else qrt+{5/t
break; H;$w^Tr
} 5[Q44$a{
} :uI}"Bp
N%Lh_2EzqV
EoOrA@N
public void splitterStop() yGN<.IP75
{ c)Y I3G$
bStop = true; *$hO C%(
} xJO[pT v
c)$/Uu
!Noabt
} qv,|7yw{
OZISh?
tcRK\
/* y:v0&9L
**FileAccess.java #z5'5|3
*//文件访问(定位，写) {AcKBib
package NetFox; *qq%)7
import java.io.*; MJ7!f+!5
J@R+t6$3O
g8vN^nQf[
public class FileAccessI implements Serializable{ >i=O =w
B!8]\D
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [IHT)%>E8&
RandomAccessFile oSavedFile; !_c<j4O
long nPos; E^|b3G6T
vn kktD'n
8`^I.tD
public FileAccessI() throws IOException X*8U%uF
{ ^pg5o)M
this("",0); Mr`u!T&sc
} 4y P $l
%*/?k~53
=e ;\I/
public FileAccessI(String sName,long nPos) throws IOException 52:oe1-8
{ S&R~*
oSavedFile = new RandomAccessFile(sName,"rw"); 1nvs51?H
this.nPos = nPos; 6*]Kow?
oSavedFile.seek(nPos); $?'z%a{
} ^ S%4R'
p?dMa_g
bJe^x;J9
public synchronized int write(byte[] b,int nStart,int nLen) [u-~<80
{ 6}<PBl%qe
int n = -1; %K/rPhU
try{ Bp4QHv9xqL
oSavedFile.write(b,nStart,nLen); KH@M & >=^
n = nLen; 0"<gg5
} n#x{~oQc
catch(IOException e) 3[8'pQ!&
{ <xc"y|7X
e.printStackTrace (); qWP1i7]=/
} Y$'fds4P
sG^b_3o)A
:v&GAs6H
return n; _b#9^2o
} FiIN\
`@`Q"J
u2!8'-Ai
} ; /EH@V|
R?I(f(ib
Q<78<#I
/* gp$+Qd
**SiteInfoBean.java .$?s :t
*/ *D|6g|Hb
package NetFox; h`5au<h<
Q_@ Z.{
f\|33)k
public class SiteInfoBean { GR|Vwxs<@P
p6jR,m8S
i:W oT4
private String sSiteURL; //Site's URL YF."D%?
private String sFilePath; //Saved File's Path K=!J=R;
private String sFileName; //Saved File's Name G\Sd!'?p
private int nSplitter; //Count of Splited Downloading File |e+I5
46$u}"E
aY"qEH7]
public SiteInfoBean() y0rT=kU
{//nSplitter的缺省值为5 9l(e:_`_
//default value of nSplitter is 5 W]rXt,{&
this("","","",5); ef|Y2<P
} -|V@zSKr3
EJL45R>
Z0E+EMo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fzw6VGTf
{ )B8[w
sSiteURL= sURL; hgsE"H<V
sFilePath = sPath; N*@bJ*0
sFileName = sName; *d(wOl5[
this.nSplitter = nSpiltter; a{]1H4+bQ
hBN!!a|l
?VReKv1\
} bZ%[ON5OY
<Z#u_:5@
V+(
public String getSSiteURL() )_+#yaC
{ >~XX'}
return sSiteURL; '+-R 7#
} yqCy`TK8
uOZ+9x(
lr^-
public void setSSiteURL(String value) KnU"49
{ `ORDN|s6
sSiteURL = value; MR8-xO'w
} `W|2Xi=^5
qr6WSBc
%s<7|,
public String getSFilePath() @tp/0E?
{ V1j&>-]]9*
return sFilePath; ym1TGeFAq
} v "oO
J!S3pS5j
~r|.GY
public void setSFilePath(String value) 9X=#wh,q
{ e2Xx7*vS
sFilePath = value; m#8KCZS
} BNaZD<<
in B}ydk
<!=TxV>}A
public String getSFileName() QmgwIz_
{ <2,@rYe/
return sFileName; 93YD\R+q
} >%d]"]
?J)%.~!
9lny[{9
public void setSFileName(String value) )Cx8?\/c=x
{ o@;w!'
sFileName = value; R_Eu*Quj
} zSkM8LM2
z.[L1AGa|s
wX|]8f2Z
public int getNSplitter() M: `FZ}&L
{ 9>zN27
return nSplitter; t7-sCC0
} z*x6V0'yt
a>s v
V&GFGds
public void setNSplitter(int nCount) )P|Ql-rE4
{ ]kc_wFT<
nSplitter = nCount; BRH:5h
} vtr:{
} vqL{~tR
sW=@G'}3
uomFE(
/* '^P Ud`
**Utility.java w*bVBuXs
*/ 0<i~XN0g
package NetFox; o AQ92~b
0.+iVOz+Y
s?_b[B d
public class Utility { 6`+DBr
#0^QUOp
/$q;-/DnTZ
public Utility() YQ?|Vb U
{ ;tKL/eI
W#??fae
3bPVKsY
} JgK?j&!hs:
s]B^Sz=
//线程睡眠 ',O@0L]L
public static void sleep(int nSecond) wmoOp;C
{ 40@KL$B=
try{ m]u#Dm7h
Thread.sleep(nSecond); J qU%$[w
} $p9XXZ"*
catch(Exception e) A+[wH(
{ 29GejLg|
e.printStackTrace (); Y,)9{T
} r3*wH1n
} 6tnAE':
pp{%\td
//日志 I5 2wTl0
public static void log(String sMsg) 4P`\fz
{ sRoZvp5
System.err.println(sMsg); t+h"YiT
} VUx~Y'b
fA+M/}=
A4&e#
public static void log(int sMsg) z?7s'2w&{
{ Rx'7tff%I
System.err.println(sMsg); O050Q5zy
} hSg:Rqnk
} 4wNxn lP
heh!cDK
7&sCEYEb
/* 83<kaeu,^
**TestMethod.java i[YYR,X|
*/ V<d'psb6
package NetFox; cBm3|@7
}!.7QpA$
-(1e!5_-@
public class TestMethod { tv;3~Y0i
-7+Fb^"L
X^@d@xU4v
public TestMethod() }B]FHpi
{ ///xx/weblogic60b2_win.exe bUqO.FZ[
try{ C{>?~@z&5
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C8n1j2G\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6=H-H\iw
SiteFileFetch fileFetch = new SiteFileFetch(bean); m+vwp\0
fileFetch.start(); [PQG]"
} rre;HJGEL
catch(Exception e){e.printStackTrace ();} MM5#B!BB
7unu-P<C
5 wc&0h
} IGI2).$[
mybDK'EW
9ge$)q@3
public static void main(String[] args) zR5D)`Ph
{ $/d~bk@=l
new TestMethod(); w]%r]PwU+
} _ !Ph1
} 2C-RoZ~
点击下载更多相关资料