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)); xv's52x
} s}`ydwSg8
for(int i=0;i<nEndPos.length-1;i++) w@nN3U+
{ ;_of'
nEndPos = nStartPos[i+1]; waQNX7Xdn
} HvK<>9
nEndPos[nEndPos.length-1] = nFileLength; ;yY>SaQ
} 3A4?9>g)KU
} #; E,>0
jIZQ/xp8_
!V Zl<|
//启动子线程 :Py/d6KK
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L/<^uO1
for(int i=0;i<nStartPos.length;i++) {08UBnR
{ iF{eGi
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), )1lR;fD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), c3P
nStartPos,nEndPos,i); -#Yg B5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9O?.0L
fileSplitterFetch.start(); /^DDU!=(<
} {]]nQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qeBfE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @?3u|m |Z
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", (#eB%
nEndPos = " + nFileLength); so8isDC'9
// fileSplitterFetch[nPos.length-1].start(); \UGs_5OT
aIRCz=N
\5k[ "8~
//等待子线程结束 1*[h$Z&H?
//int count = 0; TPq5"mco
//是否结束while循环 b3H~a2"d
boolean breakWhile = false; jkFS=eonK
r{#od 7;
w1rB"rB?
while(!bStop) e~W35Y>A
{ W.-[ceM
write_nPos(); X"y rA;,o
Utility.sleep(500); ,@khV
breakWhile = true; ]3NH[&+
`U#*O+S-^
PGP9-M
for(int i=0;i<nStartPos.length;i++) 2!-ZNd:(+
{ LP7t*}PK
if(!fileSplitterFetch.bDownOver) C=h$8Q
{ R8c1~'
breakWhile = false; :v* _Ay
break; Ol~sCr
} vE>J@g2#
} )|XmF4R
if(breakWhile) fR~_5pt7
break; k5$_Q#
J1 a/U@"
lHV bn7
//count++; vy,ER<
//if(count>4) FaPX[{_E
// siteStop(); Jq l#z/z
} =~?2i)-mC
C^aP)& qt
QSW03/_f
System.err.println("文件下载结束！"); 1[[` ^v
} u<]-%ha$
catch(Exception e){e.printStackTrace ();} TCX*$ac"
} 62PtR`b>
69!J'kM[
eq<xO28z
//获得文件长度 .D-}2<z
public long getFileSize() zM|d9TS
{ tU}CRh
int nFileLength = -1; `D>PU@s$nT
try{ 0X~
URL url = new URL(siteInfoBean.getSSiteURL()); TixHEhw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I+!w9o2nZ
httpConnection.setRequestProperty("User-Agent","NetFox"); '8 1M%KO
']ya_v~e
Zi|MWaA.f
int responseCode=httpConnection.getResponseCode(); Zuo7MR
if(responseCode>=400) {<\nl#}5S
{ R^1sbmwk
processErrorCode(responseCode); [0lCb"
return -2; //-2 represent access is error 'D1 T"}
} N~;=*)_VH
ua0`&,a3I
- A x$Y
String sHeader; d}EGI
z;zyk
sw[1T_S>
for(int i=1;;i++) L oe!@c
{ o*_[3{FU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (8?t0}#t
//Utility.log(in.readLine()); W|NzdxCY
sHeader=httpConnection.getHeaderFieldKey(i); X)e6Y{vO
if(sHeader!=null) f+}?$'
{ 6;dQ#wmg
if(sHeader.equals("Content-Length")) $LRvPan`
{ -w1U/o.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0F8y8s
break; V9`VFO
} @g }r*U?
} E b-?wzh
else ~=lm91W
break; WB'&W=
} <K=:_
} O"<D0xzF?
catch(IOException e){e.printStackTrace ();} 0vbn!<:
catch(Exception e){e.printStackTrace ();} SZpBbX$
Pz,kSxe=
Uq<c+4)5
Utility.log(nFileLength); \L}Soe'
zy(sekX;
k:Da+w_'1
return nFileLength; t.t$6+"5We
} |g;hXr#~
?SK1*; i
!>TVDN>
//保存下载信息（文件指针位置） 4`o_r%
private void write_nPos() 3!_y@sWx
{ elG<\[
try{ U; JZN
output = new DataOutputStream(new FileOutputStream(tmpFile)); \U(qv(T
output.writeInt(nStartPos.length); F-R4S^eV
for(int i=0;i<nStartPos.length;i++) ZN~:^,PO/
{ "^fcXV9Wp
// output.writeLong(nPos); H{VVxj
output.writeLong(fileSplitterFetch.nStartPos); .}&bE1
output.writeLong(fileSplitterFetch.nEndPos); 'H`aQt+
} e[$=5U~c
output.close(); 8)s}>:}
} Rb Jl;
catch(IOException e){e.printStackTrace ();} oS 7q#`
catch(Exception e){e.printStackTrace ();} 0j %s H
} -|\V'
;+'x_'a
NTASrh
//读取保存的下载信息（文件指针位置） 5D8V)i
private void read_nPos() @Hw#O33/'
{ =Bcwd7+
try{ {u{n b3/jl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); U$Z)v1&{
int nCount = input.readInt(); mHrt)0\_
nStartPos = new long[nCount]; KhIg
nEndPos = new long[nCount]; L9M0vkgri
for(int i=0;i<nStartPos.length;i++) ;{[&&qMwU
{ wHq*)7#h#
nStartPos = input.readLong(); >B<jR$`6@
nEndPos = input.readLong(); W&#Ps6)8
} [#`)Bb&w
input.close(); bgq/]fI}
} J.W0F#?
catch(IOException e){e.printStackTrace ();} X,y0J
catch(Exception e){e.printStackTrace ();} qF C0$:z&
} xok8
Hphvsre<
[`Seh$
private void processErrorCode(int nErrorCode) M>nplHq
{ tGDsZ;3Yr
System.err.println("Error Code : " + nErrorCode); LG0+A}E=C
} a'u:1C^\
C ?JcCD2
XZde}zUWn
//停止文件下载 piIj t
public void siteStop() VRQ'sn@
{ *`&4<>=n
bStop = true; 7TD%vhbiwi
for(int i=0;i<nStartPos.length;i++) z2*>5c%
fileSplitterFetch.splitterStop(); :l~Wt7R
eLWD?-v%
}G}2Y (
} %MGbIMpY
} >Vc;s!R
//负责部分文件的抓取 I!>pHF4
**FileSplitterFetch.java m<qPj"g~L
*/ {_T?0L
package NetFox; C ioM!D
o|u<tuUW
K,(37Id'
import java.io.*; *;@V5[^3I?
import java.net.*; +NWhvs
'0|0rwx
DdDwMq
public class FileSplitterFetch extends Thread { 8 :B(}Y4K
*{[jO&&J
t)o!OEnE
String sURL; //File URL g:<2yT
long nStartPos; //File Snippet Start Position 7.U CX"
long nEndPos; //File Snippet End Position MG6taOO!
int nThreadID; //Thread's ID UP]X,H~stU
boolean bDownOver = false; //Downing is over 6+`+$s0
boolean bStop = false; //Stop identical _=l8e-6r
FileAccessI fileAccessI = null; //File Access interface 3"afrA
d h5%
/`$9H|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q$IgkL
{ Jd#g"a>zZ
this.sURL = sURL; zv/owK
this.nStartPos = nStart; Y,0D+sO4
this.nEndPos = nEnd; >F7v'-*{
nThreadID = id; rUgTJx&ds
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4:m/w!q$
} .YOC|\
fP 4
2smQD8t
public void run() k6.<zs0
{ 93I.Wp_{
while(nStartPos < nEndPos && !bStop) >Z%qkU/
{ ROH 2KSt
vhsHyb
]1YyP
try{ v:.`~h/b
URL url = new URL(sURL); MYI*0o;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j!m42
httpConnection.setRequestProperty("User-Agent","NetFox"); sUl/9VKl
String sProperty = "bytes="+nStartPos+"-"; A_nu:K-
httpConnection.setRequestProperty("RANGE",sProperty); jiAKV0lX W
Utility.log(sProperty); RC{|:@]8
y*K]z
.zDm{_'
InputStream input = httpConnection.getInputStream(); |Iq#Q3w
//logResponseHead(httpConnection); )S~ySiJ<U
oW7\T!f
&4]~s:F
byte[] b = new byte[1024]; lJ y\Ky(*
int nRead; A\xvzs.d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M{)7C,'
{ oY;=$8y<q
nStartPos += fileAccessI.write(b,0,nRead); ?-.Qv1hs6p
//if(nThreadID == 1) bSbUf%LKt
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a[).'$S}'
} t^ax:6;"|
ZV,1IaO
tZ4Zj`x|^
Utility.log("Thread " + nThreadID + " is over!"); r*Iu6
bDownOver = true; @xu/&pbI
//nPos = fileAccessI.write (b,0,nRead); *21foBfqh
} b&iJui"7k
catch(Exception e){e.printStackTrace ();} Pgdv)i3
} BZUA/;Hz &
} ~r%>x
HzuB.B<
83~9Xb=!\
//打印回应的头信息 O\;R (
public void logResponseHead(HttpURLConnection con) 9pY`_lxa>
{ -hn~-Sy+
for(int i=1;;i++) ~]Md*F[4*e
{ Aw~N"i
String header=con.getHeaderFieldKey(i); A~Uqw8n$\
if(header!=null) i7 *cpNPO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +0&SXhy%y
Utility.log(header+" : "+con.getHeaderField(header)); 3d_PY,=1
else k2axGq
break; dF (m!P/R
} Lc0yLm
} xWhi>
a d,0*(</
iD/r8_}
public void splitterStop() 0qdgt
{ heF<UMI
bStop = true; QAI!/bB
} vbn'CY]QU
~-dL #;
sPKyg
} moe5H
N3C 8%
J3;dRW
/* w =MZi=p
**FileAccess.java R3`Rrj Z
*//文件访问(定位，写) `%a+LU2
package NetFox; \Gzo^w
import java.io.*; Gb?O-z%8*
$IdY(f:.:5
ab5uZ0@
public class FileAccessI implements Serializable{ i*q!|^M
c2$&pZ M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 A&dNCB
RandomAccessFile oSavedFile; {1jywb }
long nPos; #c2InwZV
s3., N|
L.]mC!
public FileAccessI() throws IOException 9F*],#ng
{ .JJ^w!|>#
this("",0); NbDfD3 1GK
} G0u3*.
.W9/*cZV0
l}Fa-9_'
public FileAccessI(String sName,long nPos) throws IOException #9Fe,
{ O8J:Tw}M*
oSavedFile = new RandomAccessFile(sName,"rw"); UdSu:V|
this.nPos = nPos; 6BPZ2EQ
oSavedFile.seek(nPos); |B0.*te6
} e>oE{_e
fK$N|r
_:tclBc8R
public synchronized int write(byte[] b,int nStart,int nLen) c=-2c&=&
{ q|8p4X}/]
int n = -1; "eH~/6A
try{ c/c%-=
oSavedFile.write(b,nStart,nLen); te+5@k#t
n = nLen; gUrb&#\X
} a%wK[yVp
catch(IOException e) {]a 6o[}u
{ R+s_uwS
e.printStackTrace (); JKFV7{%Gl
} rCmxv7" a}
8J-;/
!Qg%d&q.Sx
return n; ;[_w&"[6a
} )~](qLSl
K7x,>
,yC-QFQE
} p2=Sbb
1qs~[7{C1
$=97M.E
/* Qbc62qFu!
**SiteInfoBean.java L-ZJ[#D
*/ EmDA\9~@R
package NetFox; mQ9%[U,
\E'Nk$V3
Efb S*f5
public class SiteInfoBean { P7Th94
WAj26";M(
{,5=U@J
private String sSiteURL; //Site's URL }}GBCXAf_
private String sFilePath; //Saved File's Path 'z#{'`$a
private String sFileName; //Saved File's Name .2xp.i{
private int nSplitter; //Count of Splited Downloading File !n`ogzOh
jH*+\:UP-
%;.|?gR
public SiteInfoBean() %5_eos&<^)
{//nSplitter的缺省值为5 ,u}n!quA
//default value of nSplitter is 5 ==psPyLF@
this("","","",5); i*9[El
} `TkIyGr
mne^PSI:
?-FSDNQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]`D(/l'
{ ^}2 ie|
sSiteURL= sURL; zS:89y<
sFilePath = sPath; lPS A
sFileName = sName; g~L1e5C]z
this.nSplitter = nSpiltter; zXB]Bf3TH
?80@+y]
+ R)x5
} {-rK:*yP'u
-=E/_c;
yG0Wr=/<?
public String getSSiteURL() mI=^7'Mk
{ b'$j* N
return sSiteURL; yaf&SR@7k{
} @1#$
vf@d(g
sz.(_{5!
public void setSSiteURL(String value) blZiz2F
{ ~6'6v8
sSiteURL = value; P,"z
} {Izg1N
xG_ ;F
{rWu`QT
public String getSFilePath() N0c+V["s
{ a9GOY+;bf
return sFilePath; b`n+[UCPtn
} DPnKr/
{uO8VL5+Qx
9p!V?cH#8
public void setSFilePath(String value) n=RAE^[M
{ XN"V{;OP1
sFilePath = value; Z'GOp?
} /UjRuUC]
NQ<~$+{
I}Z[F,}*J
public String getSFileName() -A9 !Y{Z
{ Y#PbC
return sFileName; ~(B\X?v
} v&(X&q
2 G_*Pqc
a#1LGH7E8
public void setSFileName(String value) L{~L6:6An
{ tc@U_>{
sFileName = value; 5(MWgC1
} >TsJ0E?3x
%^"Tz,f
IxCEE5+`%
public int getNSplitter() .i/]1X*;r^
{ (0W%YZ!&
return nSplitter; `QR2!W70o3
} N_L&!%s
Bh*~I_Ta>
Z`"UT#^SI
public void setNSplitter(int nCount) "zw?AC6
{ Ul[>LKFY
nSplitter = nCount; p;j$i6YJ
} 0|{U"\
} ]t1)8v2w>
N|Ua|^
ywk;
/* P58U8MEG
**Utility.java rK~362|mo
*/ K 3&MR=#^
package NetFox; 5d(A(
O6OP{sb
9Pd~
public class Utility { a-Cp"pKlVY
PZpwi?N
~>D;2 S(a
public Utility() d"XS;;l%<
{ 5]; 8
ru(Xeojv#
6kT l(+
} xbo-~{
g$dL5N7
//线程睡眠 Ph]e\
public static void sleep(int nSecond) $Miii`VS9
{ $2>tfKhtA
try{ ~<v.WP<:
Thread.sleep(nSecond); ]rn!+z
} WGG|d)'@
catch(Exception e) B0q![
{ K;6K!6J:[
e.printStackTrace (); l$,l3
} *&UVr
} y%TR2CvT
Jkm\{;
//日志 2WE
public static void log(String sMsg) I6y&6g
{ yc]ni.Hz
System.err.println(sMsg); "XC6 l4Z
} H gNUr5p
h#]}J}si
<mY`<(bc
public static void log(int sMsg) <?qmB}Y
{ J-?\,N1R7
System.err.println(sMsg); N>ct`a)BD/
} w,3`Xq@
} !kASEjFz|f
.&@|)u
>w j7Y`
/* jI;bVG
**TestMethod.java q3NS?t!
*/ tx5_e[
package NetFox; 308w0eP
?]9uHrdsN}
aE#ZTc=
public class TestMethod { &1Cq+YpI
d'[aOH4}
0E\R\KO$>
public TestMethod() D<++6HN&#
{ ///xx/weblogic60b2_win.exe Mh+'f 93
try{ >j`*-(`2fa
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [b#jw,7
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); p6Z]oL q
SiteFileFetch fileFetch = new SiteFileFetch(bean); i $I|JJJ
fileFetch.start(); :-"J)^V
} F|P2\SPL
catch(Exception e){e.printStackTrace ();} oN `tZ;a
#mkr]K8A4
[PX'Jer
} n;Iey[7_E`
/WHhwMc!
m]"YR_
public static void main(String[] args) wkJB5i^<w
{ LG<lZ9+y
new TestMethod(); 7abq3OK+`
} Z:/S@ry
} Qgx~'9
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