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)); U{KnjoS
} D66NF;7q
for(int i=0;i<nEndPos.length-1;i++) uts>4r>+
{ jU kxA7 }}
nEndPos = nStartPos[i+1]; 0VrsbkS
} L }3eZ-
nEndPos[nEndPos.length-1] = nFileLength; @ze2'56F}
} (c&%1bJ
} +*w}H 0Z
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ZPY&q&R
//启动子线程 h1"|$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ch3MwM5]
for(int i=0;i<nStartPos.length;i++) V%)Tu{L
{ .heU Ir,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }zS5o [OE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dC8}Ttc}
nStartPos,nEndPos,i); )#8g<]q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WF-jy7+
fileSplitterFetch.start(); p!8phS#iP
} gwsIzYV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n((A:b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'e*w8h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9gdK&/ulR
nEndPos = " + nFileLength); AC'_#nPL#
// fileSplitterFetch[nPos.length-1].start(); MoQ\~/Z|
XXhN;-p
3^nH>f-Y
//等待子线程结束 /:Gy .
//int count = 0; $|@vmv0
//是否结束while循环 7)Vbp--b#
boolean breakWhile = false; lZ7 $DGe
<xF]ca
T)OR HJ&,
while(!bStop) z6l'v~\
{ *!JB^5(H
write_nPos(); j)Ak:l%a
Utility.sleep(500); d@1^U9sf
breakWhile = true; v*qbzW`
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?>7-a~*A@
for(int i=0;i<nStartPos.length;i++) +0z7}u\x
{ NN=^4Xpc:
if(!fileSplitterFetch.bDownOver) kE.4 #
{ NU?<bIQ
breakWhile = false; "O0xh_Nr
break; !&hqj$>-}
} Dol{y=(3e
} Jy%?"wn
if(breakWhile) tE{M
break; MjQju@
{4,],0bjx/
j}",+Hv
//count++; dd<l;4(
//if(count>4) Ikf[K%NKn
// siteStop(); 5|*`} ;/y
} \>Rfa+
T:Nk9t$W7@
'UWkJ2:!
System.err.println("文件下载结束！"); qf\W,SM
} n`&D_AbQ
catch(Exception e){e.printStackTrace ();} T9w=k)
} E5)0YYjHZ
} v:YSG
[V:~j1{3
//获得文件长度 )]FXUz|;
public long getFileSize() \q1tT!]
{ 6{]F#ig=
int nFileLength = -1; dB[4NT
try{ EG3,TuDH8
URL url = new URL(siteInfoBean.getSSiteURL()); Rh|9F yN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `sT;\
httpConnection.setRequestProperty("User-Agent","NetFox"); >d p/
*$-X&.h[
2I}pX9
int responseCode=httpConnection.getResponseCode(); ;Go^)bN ;
if(responseCode>=400) gtu<#h(
{ }rfikm
processErrorCode(responseCode); w=WF$)ZU
return -2; //-2 represent access is error |*NZ^6`@
} mXp#6'a
z80P5^9
"4\
String sHeader; 8.B'O>\T
196a~xNV
gPMfn:a-8
for(int i=1;;i++) HbA/~7
{ vnvpb! @Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =eQB-Xe8Y
//Utility.log(in.readLine()); Q*>)W{H&)
sHeader=httpConnection.getHeaderFieldKey(i); ErK1j
if(sHeader!=null) /_qq(,3
{ 6(`N!]e*L
if(sHeader.equals("Content-Length")) 'l.tV7
{ js81@WX!c
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); T(*,nJi~9
break; CLaQE{
} baII!ks
} 80@\e
else Th9V8Rg+E
break; V)<>W_g
} Yn~fnI{
} gE2(E0H
catch(IOException e){e.printStackTrace ();} f $Agcy
catch(Exception e){e.printStackTrace ();} H:~p5t
^~[7])}g6
TI7$J#
Utility.log(nFileLength); DPzW,aIgv
7_1 Iadb
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return nFileLength; Zt3sU_
} pKc!sdC
Og7yT{h_
$?PI>9g!
//保存下载信息（文件指针位置） jum"T\
private void write_nPos() o&1mX
{ lz0-5z+\
try{ L[2qCxB'^
output = new DataOutputStream(new FileOutputStream(tmpFile)); I_ZJnu<
output.writeInt(nStartPos.length); _s^tL2Pc
for(int i=0;i<nStartPos.length;i++) 71nZi`AR
{ m0bxVV^DK!
// output.writeLong(nPos); Mgw#4LU
output.writeLong(fileSplitterFetch.nStartPos); oWY3dc
output.writeLong(fileSplitterFetch.nEndPos); 7#E/Q~]'6
} $vXY"-k
output.close(); Z2]0brV
} uQW)pD{_
catch(IOException e){e.printStackTrace ();} daKZ*B|
catch(Exception e){e.printStackTrace ();} -NwG' U~
} CB#2XS>V
\XB,)XDB
b;QgL_w
//读取保存的下载信息（文件指针位置） v"1&xe^4
private void read_nPos() XE2Un1i}j1
{ eV?%3h.
try{ :5~Dca_iU4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Sn-#Y(>]o0
int nCount = input.readInt(); nN{DO:_o
nStartPos = new long[nCount]; l\{Qnb(
nEndPos = new long[nCount]; ZvF#J_%gE5
for(int i=0;i<nStartPos.length;i++) yT/rH- j;5
{ nr]=O`Mvh
nStartPos = input.readLong(); @JlT*:Dz
nEndPos = input.readLong(); i<Ms2^
} [s^pP2
input.close(); fh =R
} \>:t={>;
catch(IOException e){e.printStackTrace ();} Gk5'|s
catch(Exception e){e.printStackTrace ();} j4i$2ZT'
} {O _X/y~
Bdh*[S\u@E
bnfeZR1m_
private void processErrorCode(int nErrorCode) q,fp DNo
{ PNAvT$0LaZ
System.err.println("Error Code : " + nErrorCode); my sXgS&S
} xCL)<8[R,}
l#cVQ_^"
uO1^Q;F
//停止文件下载 M{p6&eg
public void siteStop() RbUir185Y
{ 2+pw%#fe
bStop = true; {@KLN<
for(int i=0;i<nStartPos.length;i++) =Jl\^u%H(x
fileSplitterFetch.splitterStop(); E~q3o*
~*EipxhstJ
Z%o.kd"
} MMa`}wSs
} 9Y2u/|!.3
//负责部分文件的抓取 3SWDPy
**FileSplitterFetch.java VT>-*
*/ Q']'KU.
package NetFox; '(r?($s
rs4:jS$)
KD#zsL)3
import java.io.*; =X'EDw
import java.net.*; N/-(~r[
;Uch
0e>?!Z E
public class FileSplitterFetch extends Thread { <EyJ $$
G{.=27
~*h)`uM
String sURL; //File URL 2FL_!;p;2E
long nStartPos; //File Snippet Start Position mn1!A`$
long nEndPos; //File Snippet End Position XH0{|#hwN
int nThreadID; //Thread's ID q@1A2L\Om
boolean bDownOver = false; //Downing is over Q>yj<DR
boolean bStop = false; //Stop identical or ~@!
FileAccessI fileAccessI = null; //File Access interface dG3?(}p+
Wsd_RT}ww
x?6^EB|@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cJT_Qfxx
{ 2hntQ1[
this.sURL = sURL; aG"
this.nStartPos = nStart; 5-a^Frmg#"
this.nEndPos = nEnd; L) _ VdB
nThreadID = id; ]%7m+-h@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 oMn'{+(w
} /jaO\t'q
3Qv9=q|[b
K:4G(?w
public void run() z,qNuv"W
{ 4wS!g10}
while(nStartPos < nEndPos && !bStop) /$8& r
{ oPAc6ObOV~
>&Ye(3w&
K/(Z\lL
try{ }&ew}'*9)
URL url = new URL(sURL); +ZwTi!W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l9rN!Q|
httpConnection.setRequestProperty("User-Agent","NetFox"); 00W_XhJ
String sProperty = "bytes="+nStartPos+"-"; %&O'>L
httpConnection.setRequestProperty("RANGE",sProperty); dZJU>o'BG
Utility.log(sProperty); 5',b~Pp
"g!/^A!!
TTxSl p2=;
InputStream input = httpConnection.getInputStream(); :OaGdL
//logResponseHead(httpConnection); =:RNpi,
HBa6Y&)<
Fw#wVs)@:
byte[] b = new byte[1024]; (yeN> x}_
int nRead; +zFEx%3^
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) KC\W6|NtGj
{ \y/0)NL\
nStartPos += fileAccessI.write(b,0,nRead); 3A b_Z
//if(nThreadID == 1) 7sJGB^vM
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p_sqw~)^%
} BI6`@}%7>
PPtJ/ }\
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Utility.log("Thread " + nThreadID + " is over!"); cmLI!"RLe
bDownOver = true; |SsmVW$B|
//nPos = fileAccessI.write (b,0,nRead); +m6acu)N.
} +Kg3qS"
catch(Exception e){e.printStackTrace ();} %t-}dC&
} *5'l"YQ@1
} w>#.id[k
y{qKb:~wv
x8h=3e$
//打印回应的头信息 <dhBO
public void logResponseHead(HttpURLConnection con) xHwcP21
{ Ils^t
for(int i=1;;i++) )RwO2H
{ (<5&<JC{
String header=con.getHeaderFieldKey(i); Yh;A
if(header!=null) \E:l E/y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;ZLfb n3\
Utility.log(header+" : "+con.getHeaderField(header)); HFf9^
else =Cr F(wVO"
break; A v%'#1w<"
} @$d_JwI
} q0]Z` <w
4EEXt<c.
/H[!v:U
public void splitterStop() ,n+~S^r
{ +QVe -
bStop = true; -qndBS
} %L;'C v
0_-NE4SM/
qc`UDD5
} < {dV=
-7l)mk
xu0pY(n^r
/* T$;N8x[
**FileAccess.java 8a4&}^|
*//文件访问(定位，写) 0xg6
package NetFox; E; Z1HF R
import java.io.*; vy330SQPo
UKxeN[fv
-( ,iwFb
public class FileAccessI implements Serializable{ t{)J#8:g
x?B8b-*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^iq$zHbc0u
RandomAccessFile oSavedFile; {n>W8sN<
long nPos; HNtl>H
SLG3u;Ab
d4zqLD$A
public FileAccessI() throws IOException PXYo@^ 3
{ 0Bpix|mq
this("",0); _n+./B
} ^g56:j~?
\!4sd2Yi
W=T}hA#`
public FileAccessI(String sName,long nPos) throws IOException xc+h Fx
{ J<{@D9r9<~
oSavedFile = new RandomAccessFile(sName,"rw"); -Fj:^q:@u
this.nPos = nPos; Qm\VZ<6/5
oSavedFile.seek(nPos); )0:@T)G
} jreY'y:
c*g(R.!
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public synchronized int write(byte[] b,int nStart,int nLen) OW12m{
{ .Lk2S "+
int n = -1; qeyBZ8BG
try{ *?`:=
oSavedFile.write(b,nStart,nLen); u&>o1!c*P
n = nLen; y^oSVj
} @edi6b1W
catch(IOException e) J!:ss
{ AdtAc$@xK
e.printStackTrace (); WBA0! g98
} ;Vad| -
j/R
Q b5AQf30
return n; #n'tpp~O
} $e! i4pM
(,E.1j]ji
TWC^M{e
} ^AUmIyf_
`bGAc&,&
m#'2 3
/* SLc6]?
**SiteInfoBean.java /R< Q~G|\
*/ :G|Jcl=r
package NetFox; Aov=qLWJ
~h;c3#wuc
~<pGiW'w5
public class SiteInfoBean { AR?J[e
zb}:wUR
ztG_::QtG]
private String sSiteURL; //Site's URL ,2)LH'Xx
private String sFilePath; //Saved File's Path Frt_X%
private String sFileName; //Saved File's Name !V.'~xj
private int nSplitter; //Count of Splited Downloading File p3*}!ez4
& h9ji[
-O_5OT4
public SiteInfoBean() =F ZvtcCa
{//nSplitter的缺省值为5 itM6S$
//default value of nSplitter is 5 ]7ROCJ;
this("","","",5); im_W0tGvF
} p~28?lYv
@R?S-*o
NrTQ}_3)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fAfsKO*
{ U]fE(mpI9
sSiteURL= sURL; TE0hVw0c
sFilePath = sPath; |-I[{"6q$@
sFileName = sName; JPgV7+{b[
this.nSplitter = nSpiltter; A%u-6"
-ny[Lh^b
7,_N9Q]rB
} /+Xv(B
b IcLMG s
9xC,i )
public String getSSiteURL() u Y/Q]NT
{ VVvV]rU~
return sSiteURL; Rw*l#cr=.
} 7[:9vY
Jk|c!,!
]E88zWDY`
public void setSSiteURL(String value) ,~gY'Ql
{ 5FnWlFc
sSiteURL = value; 4W~pAruwr
} x\!Qe\lE
N/Z3 EF_
+%8c8]2
public String getSFilePath() goeWZO
{ $TL~SVHj;{
return sFilePath; G1vWHa7n;f
} *8fnxWR
Ezm ~SY
93[c^sc9*a
public void setSFilePath(String value) bJ]g2C7`36
{ 8,#v7ns}#
sFilePath = value; }f<.07
} ;c_X ^"d
%s%v|HDs
U"A]b(54
public String getSFileName() 4_8%ZaQ\.?
{ x;l\#x/<
return sFileName; Lcf =)GL
} M$ `b$il
9@#Z6[=R,
Z'>Xn^
public void setSFileName(String value) ( N~[sf?&
{ #]oVVf_
sFileName = value; k;R*mg*K
} c</d1xT
{%'(IJ|5z
dOqn0Z
public int getNSplitter() ^UZEdR;
{ <K%qaf
return nSplitter; ync2X{9D
} .%h.b6^
T/V8&'^i
E#`=xg
public void setNSplitter(int nCount) bBc<yaN
{ _y#t[|}w
nSplitter = nCount; ><viJ$i
} D%N^iJC,9
} G%
E5UI
PCH&eTKN
/* 8xs[{?|:
**Utility.java 3<1Uq3Pa
*/ DKAqQ?fS
package NetFox; (YF`#v6
H2l/9+
E'?yI'~=
public class Utility { "GEJ9_a[
Lo\+T+n
2K'3ry)[y
public Utility() 2i;G3"\
{ ^]3Y11sI
>c*}Do{lG
1hw1AJ}(F
} 5e~\o}]
a?/GEfd
//线程睡眠 %Wkvo-rOq
public static void sleep(int nSecond) .$y}}/{j?[
{ qvy~b
try{ Jiyt,D*wX
Thread.sleep(nSecond); tI0d!8K
} iY1%"x
catch(Exception e) Fd*)1FQKT
{ L}*:,&Y/
e.printStackTrace (); "rOe J~4 X
} o7)<pfif
} 2`tdH|Z`
?2zVWZ
//日志 I *YO
public static void log(String sMsg) 9>\P]:
{ 47.c
System.err.println(sMsg); =T;>$&qs
} !'o5X]s
55MrsiW
&^3KF0\Q
public static void log(int sMsg) YjN2 ,Xi
{ / PDe<p
System.err.println(sMsg); 8\+kfK
} P,r9<
} 23 j{bK
*{8<4CVv
eL3HX _2(
/* dznHR6x
**TestMethod.java 83~ Gu[
*/ 20750G
package NetFox; KKP}fN
eIBHAdU+g/
JRt^YX
public class TestMethod { ~WXT0-,
hfT HP
0`.3`Mk
public TestMethod() qD=o;:~Km
{ ///xx/weblogic60b2_win.exe p?(w!O
try{ /cHd&i,>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0vOt.LC/S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); AoB~ZWq
SiteFileFetch fileFetch = new SiteFileFetch(bean); M:x?I_JG8
fileFetch.start(); 8}9|hT;
} R|aA6} /I
catch(Exception e){e.printStackTrace ();} {* S8n09v
np3$bqm
4|*b{Ni
} R\k= CoJJ
par|j]
i(R&Q;{E^
public static void main(String[] args) "8MG[$Y
{ dYEF,\Z'
new TestMethod(); .2?txOKh
} *lHI\5
} Q-([3%
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