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)); 7DIIx}A
} jLpc Zb,
for(int i=0;i<nEndPos.length-1;i++) de>v
{ NcP.;u;`
nEndPos = nStartPos[i+1]; {;.T7dL
} Oi:<~E[kz.
nEndPos[nEndPos.length-1] = nFileLength; ?c7*_<W5
} A?`jnRo=\
} +QE^\a
1.gG^$Jd
TEMw8@b
//启动子线程 G 2mX;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,}:G\u*Fu
for(int i=0;i<nStartPos.length;i++) wbe<'/X+
{ k%E2n:|*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 04*6(L)h*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KID,|K
nStartPos,nEndPos,i); A0Zt8>w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \#rIQOPl?
fileSplitterFetch.start(); Vo7dAHHL
} OX"j#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;\[(- )f!=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y|Ir._bt
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8,atX+tc
nEndPos = " + nFileLength); k<cgO[m
// fileSplitterFetch[nPos.length-1].start(); E=cwq"
.58qL-iC
4WE6fJ2X
//等待子线程结束 gt/zpiKmV
//int count = 0; ;L,mBQB?0b
//是否结束while循环 fPrLM'
boolean breakWhile = false; &`fhEN
{&"L~>/o
QjC22lW-
while(!bStop) tOOchu?=
{ iC*F
write_nPos(); #^4,GLIM
Utility.sleep(500); JMVNmq&0
breakWhile = true; NHl|x4Zpw
=b[_@zq]
TARXx>
for(int i=0;i<nStartPos.length;i++) (%U@3._
{ E"L2&.
if(!fileSplitterFetch.bDownOver) 6:]*c[7
{ 06Gt&_Q
breakWhile = false; ;A'":vXmc
break; cW{1 Pz^_
} }=v)Js
} f}L*uw
if(breakWhile) 0jzbG]pc:E
break; JICawj:I
meCC?YAB
W,K%c=
//count++; e4G4GZH8
//if(count>4) '*Almv{
// siteStop(); YOrrkbJ(
} E7Ulnvd
8kbY+W%n
g/&T[FOr
System.err.println("文件下载结束！"); I(S)n+E
} Cn_$l>
catch(Exception e){e.printStackTrace ();} iA,kX\nK
} >OP+^^oZ<
f"(X(1F
c5Q<$86
//获得文件长度 n3lE,b
public long getFileSize() kEO7PK/
{ 0[F:'_
int nFileLength = -1; fS:1^A2,
try{ @m?QR(LJ
URL url = new URL(siteInfoBean.getSSiteURL()); !I\!;b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &h~Xq^
httpConnection.setRequestProperty("User-Agent","NetFox"); 4HAp{a1
||zb6|7I4
:iiw3#]
int responseCode=httpConnection.getResponseCode(); >I<r)w]
if(responseCode>=400) )?2e
{ #eN{!Niy&U
processErrorCode(responseCode); )9S>ZZF
return -2; //-2 represent access is error }@+NN ?P
} q\rC5gk>
#XnPsU<J
$o+5/c?|
String sHeader; !;Jmg
BI:k#jO!
*0_yT$
for(int i=1;;i++) w0ZLcND{
{ 7?v#'Ies
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2qi'g:qe
//Utility.log(in.readLine()); /cK%n4l.y
sHeader=httpConnection.getHeaderFieldKey(i); IG?'zppjd6
if(sHeader!=null) m'-|{c
{ `funE:>,
if(sHeader.equals("Content-Length")) `]v[5E
{ )>7%pz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); o&hIHfZri
break; Jd,)a#<j
} f1PN|
} E`j-6:
else i-U4RZE
break; za'6Y*CGgX
} 1 ^g t1o
} |+U<S~
catch(IOException e){e.printStackTrace ();} =&dW(uyzY
catch(Exception e){e.printStackTrace ();} 7DKz;o
)s9',4$eK<
$DBGLmw
Utility.log(nFileLength); @FN*TJ
~dHM4lGY
|BZDhd9<{
return nFileLength; PS S?|Vk
} d/74{.
O8U<{jgAG
!TAp+b
//保存下载信息（文件指针位置） as+GbstN
private void write_nPos() $3X-rjQtW
{ O|cu.u|
try{ %~NH0oFO
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZAuWx@}
output.writeInt(nStartPos.length); qpJ{2Q
for(int i=0;i<nStartPos.length;i++) t!1$$e?`r
{ 7*wVI+
// output.writeLong(nPos); rg_Q"g
output.writeLong(fileSplitterFetch.nStartPos); "Dy'Kd%,%/
output.writeLong(fileSplitterFetch.nEndPos); Z.i{i^/#(
} %b?$@H-Re
output.close(); ^")F7`PF
} r,(et
catch(IOException e){e.printStackTrace ();} nsb4S{
catch(Exception e){e.printStackTrace ();} I1U7.CT
} 6 fz}
jy2IZ o
.7ayQp
//读取保存的下载信息（文件指针位置） /q\_&@
private void read_nPos() Hqz?E@bc@
{ Wk4.%tpeO7
try{ G+*cpn
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); B6}FIg)
int nCount = input.readInt(); Dbx~n#nG
nStartPos = new long[nCount]; <uP^-bv;(
nEndPos = new long[nCount]; 5wC* ?>/
for(int i=0;i<nStartPos.length;i++) ]J2:194
{ lo&#(L+2
nStartPos = input.readLong(); Gi^Ha=?J%
nEndPos = input.readLong(); .wrL3z_
} $\a5&1rl
input.close(); :Zw@yt
} MVv1.6c7Y
catch(IOException e){e.printStackTrace ();} {}>n{_
catch(Exception e){e.printStackTrace ();} Aw!gSf)
} ^]p
/DS?}I.*]
ps:f=6m2
private void processErrorCode(int nErrorCode) P`1EPF
{ _DPOyR2
System.err.println("Error Code : " + nErrorCode); FrTg4
} 0m9ZQ O
{Z{o"56f
'_+9y5
//停止文件下载 ^b?2N/m@
public void siteStop() 24\gbv<
{ PHM:W%g:
bStop = true; "L&k)J
for(int i=0;i<nStartPos.length;i++) g+zJ?
fileSplitterFetch.splitterStop(); u3tZ[Y2 c
(9fdljl],:
a?cn9i)#
} $<?X7n^
} @=]8^?$t 0
//负责部分文件的抓取 Md;/nJO~{
**FileSplitterFetch.java VU!w!GN]Y
*/ -[#n+`M
package NetFox; M"^K0 .
yfjXqn[Z4
QYE7p\
import java.io.*; WNa0,
import java.net.*; ek-!b!iI
U!q[e`B
eQX`,9:5
public class FileSplitterFetch extends Thread { iT)WR90
q(z7~:+qNr
eTE2J~\
String sURL; //File URL Z&yaSB
long nStartPos; //File Snippet Start Position ,WTTJN
long nEndPos; //File Snippet End Position XbvDi+R2A
int nThreadID; //Thread's ID OjnJV
boolean bDownOver = false; //Downing is over R 4EEelSZu
boolean bStop = false; //Stop identical uf)Oy7FQ
FileAccessI fileAccessI = null; //File Access interface JSMPyj
h%#_~IA:|
uVU`tDzd:
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h#f&|*Q5m
{ aSnp/g
this.sURL = sURL; CUmH,`hu
this.nStartPos = nStart; 89eq[ |G_
this.nEndPos = nEnd; d;suACW
nThreadID = id; %|Hp Bs#'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~\_T5/I%
} .{rbw9
M?6;|-HH
<4?*$
public void run() }~enEZ
{ 5h_5Z~
while(nStartPos < nEndPos && !bStop) 6nw&$I
{ ,a(O`##Bn
Wpm9`K
H*!5e0~rR
try{ 4Z%Y"PL(K
URL url = new URL(sURL); X.J
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /#q")4Mf
httpConnection.setRequestProperty("User-Agent","NetFox"); /(6zsq'v|
String sProperty = "bytes="+nStartPos+"-"; }ymvC
httpConnection.setRequestProperty("RANGE",sProperty); #Q6w+"
Utility.log(sProperty); ]if;A)'
{/UhUG
I"Q<n[g0'
InputStream input = httpConnection.getInputStream(); [ #]jC[
//logResponseHead(httpConnection); z%2w(&1
Kmry=`=A
!]DuZ=
byte[] b = new byte[1024]; )bW<8f2
int nRead; X=_Z(;<&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kO3`54
{ H@!#;w
nStartPos += fileAccessI.write(b,0,nRead); D9,! %7i
//if(nThreadID == 1) m6so]xr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )A83A<~
} #MM&BC
IRB& j%LA
%-^}45](q
Utility.log("Thread " + nThreadID + " is over!"); g,?\~8-c
bDownOver = true; !kh{9I>M
//nPos = fileAccessI.write (b,0,nRead); $N\+,?
} q+/l"&j.
catch(Exception e){e.printStackTrace ();} BjD&>gO)
} EzP#Mnz^
} m "]!I~jd
AVpuMNd@
Ow3a0cF[9
//打印回应的头信息 ,C!n}+27
public void logResponseHead(HttpURLConnection con) kMS5h~D[
{ eY3=|RR
for(int i=1;;i++) |!b9b(_j9
{ {})y^L
String header=con.getHeaderFieldKey(i); ZlM_m >,o
if(header!=null) (v;A'BjN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3}4#I_<$F@
Utility.log(header+" : "+con.getHeaderField(header)); @&:VKpu\
else uX0 Bp8P
break; d^SE)/j
} Qp69Sk@H{
} Y\8+}g;KR
\dNhzd#
"t+r+ipf])
public void splitterStop() N9*UMVU
{ zlMlMyG4
bStop = true; W?PWJkIw
} hT=f;6$
*f*f&l%
!rHx}n{rw
} TolrEcI
9Z9l:}bO
.\4l'THn,0
/* K{FhT9R'
**FileAccess.java Z!)f*
*//文件访问(定位，写) rIPl6,w~
package NetFox; `r.N
import java.io.*; ~h|m&XK+Q
|$Xf;N37t
thQ J(w
public class FileAccessI implements Serializable{ )8]3kQffJ=
$O]^Xm3{@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 g 2#F_
RandomAccessFile oSavedFile; M\jB)@)
long nPos; %(NN*o9"q
dk4D+*R
UFk!dK+
public FileAccessI() throws IOException pg5&=
{ r$?Vx_f`Q
this("",0); i"fCpkAP
} ;r=?BbND?
f~v"zT
b\M b*o
public FileAccessI(String sName,long nPos) throws IOException 3 9yz~
{ VK$zq5D
oSavedFile = new RandomAccessFile(sName,"rw"); Nc"NObe
this.nPos = nPos; H CuK
oSavedFile.seek(nPos); um{e&5jk
} w?/f Zx
omT(3)TP
My0!=4Any
public synchronized int write(byte[] b,int nStart,int nLen) QP<FCmt8
{ ?GfxBZWJ
int n = -1; ip674'bq7R
try{ jB/V{Y#y9@
oSavedFile.write(b,nStart,nLen); 6*V8k%H
n = nLen; lkN'uZ
} E7gL~4I
catch(IOException e) ,-!2 5G
{ ^Bn1;
e.printStackTrace (); =lm nzu<
} @Z"?^2
iU,/!IQ
_4Ii5CNNU
return n; 8}9Ob~on
} Djyp3uUA/
m"q/,}DR
}eI`Qg
} CCn/ udp@
e-jw^
" C&x,Ic
/* IF^[^^v+H
**SiteInfoBean.java dGa@<hg
*/ %/X2 l
package NetFox; }oV3EIH
!b'IfDp[-!
^}tLnF
public class SiteInfoBean { wyNC|P;j$g
=}"R5
"W3W:vl!
private String sSiteURL; //Site's URL &6Ns7w6*z
private String sFilePath; //Saved File's Path q< b"M$
private String sFileName; //Saved File's Name HmFNE$k
private int nSplitter; //Count of Splited Downloading File l-Fmn/V
m_(E(_
M;V&KGZ
public SiteInfoBean() aDXpkG0E
{//nSplitter的缺省值为5 i{P%{hVb
//default value of nSplitter is 5 kO jEY
this("","","",5); +fPNen4E
} NuIT{3S
w}"!l G
|E? ,xWN
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0}6QO
{ J/L)3y
sSiteURL= sURL; +&(Jn
sFilePath = sPath; <Ak:8&$O
sFileName = sName; 6(,ItMbI
this.nSplitter = nSpiltter; N:twq&[Y
oO8]lHS?@
9A(n_Rs7?
} G]at{(^Vz
EgFl="0
l<s :%%CX
public String getSSiteURL() " S ?Km
{ _dJp 3D
return sSiteURL; ys/`{:w8p
} gZ1N&/9;
%bEGv:88s
i_|h{JK)
public void setSSiteURL(String value) ;B*L1'FF%t
{ =z+-l5Gu"
sSiteURL = value; JN-D/s
} N&x@_t""
5 Xk~,%-C
>\Z lZ
public String getSFilePath() mf+K{y,L
{ `CPZPp,l6`
return sFilePath; s z;=mMr/Z
} md.*
}R4(B2vup
zwKg
public void setSFilePath(String value) ~WzMK
{ (H'_KPK
sFilePath = value; GOUY_&}tL
} =;kRk.qzy
>3<&V{<K
Dr4?Ow
public String getSFileName() WW)_Wh
{ 5dbX%e_OP
return sFileName; 6-D%)Z(
} ?SHc}iaU#
yjeqv-7
I|GV :D
public void setSFileName(String value) J11dqj
{ Pw0{.W~r
sFileName = value; `'dX/d
} =c :lS&B
>ly&+3S
!a.3OpQ
public int getNSplitter() W ]a7&S
{ FRb&@(;
return nSplitter; mMel,iK=
} /%2:+w
\Sz4Gr0g3Z
V22q*/iV
public void setNSplitter(int nCount) Uh<H*o6e 9
{ dw|-=~
nSplitter = nCount; DMy4"2 o
} qpluk!
} \r:m({G
,{#RrF e
5JJg"yuY"
/* t't^E,E .@
**Utility.java v'mJ~tz
*/ f(EYx)gZ
package NetFox; s^{{@O.
8Cf^$
-MVNXAKnZ
public class Utility { ; |E! |w
3C E 39W
F]dmc,Q
public Utility() UXcH";*9b
{ >[A65q'
Om&{4a\
GQEIf$
} A>rWGo.{E
EZgxSQaPH
//线程睡眠 Pf^Ly97
public static void sleep(int nSecond) O=4ceEmz
{ /6Jy'"+'0
try{ 3G:NZ)p
Thread.sleep(nSecond); ,"v)vTt
} #dxJ#
catch(Exception e) !W+p<F1i
{ 6KBzlj0T+
e.printStackTrace (); Q6s5#7h'"
} Kt/+PS
} iA1;k*)q
W(]E04
//日志 y \mutm
public static void log(String sMsg) a:(: :m
{ "(HA9:
System.err.println(sMsg); |wyJh"4!
} yhJA;&}>
*Bb|N--jI
dA_V:HP
public static void log(int sMsg) \E ? iw.}
{ C7XS6Nqu
System.err.println(sMsg); (}/.4xE
} R-2FNl
} ,YAPCj
d~P<M3#>
i_jax)m%
/* #NVF\
**TestMethod.java GDNh?R
*/ <MWXew7b
package NetFox; ~|0F?~eR7
T9U2j-lA?
E9Qd>o
public class TestMethod { 3& fIO
/z.7:<gZ(
{8*d;[X50
public TestMethod() [EW$7 se~
{ ///xx/weblogic60b2_win.exe )$Dcrrj
try{ N c&i) qh
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y.ivz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &?5{z\;1"
SiteFileFetch fileFetch = new SiteFileFetch(bean); 6S&=OK^
fileFetch.start(); 9wDBC~.
} u]>>B>KOJ7
catch(Exception e){e.printStackTrace ();} :<WQ;q
I!soV0VU]
b[&,%Sm+6
} BC$;b>IUA
&ttv4BC^r
^!v}
public static void main(String[] args) 7/U<\(V!g
{ s&QBFyKtJ
new TestMethod(); &Curvc1fm
} TJ%]{%F
} q|]0on~]
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