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)); ^d@2Y0hH
} jD%|@ux
for(int i=0;i<nEndPos.length-1;i++) g"k4Z
{ KVh#"]<WV
nEndPos = nStartPos[i+1]; TZ `Ypi7r
} ~Uey'Xz
nEndPos[nEndPos.length-1] = nFileLength; ^G2M4+W|
} !tcz_%
} 5Zd oem
ecQ{ePoU
'2hy%
//启动子线程 >*opEI+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .9WOTti
for(int i=0;i<nStartPos.length;i++) 5!cp^[rGL
{ TUz4-Pd
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), j7QK8O$XL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /!^,+
nStartPos,nEndPos,i); [ZC\8tP`V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MBU|<tc
fileSplitterFetch.start(); 0[M2LF!m
} 2K{'F1"RM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {I0U 4]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); UP$>,05z6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Yh!=mW!OY
nEndPos = " + nFileLength); %p$XK(6
// fileSplitterFetch[nPos.length-1].start(); X 6tJ
M:/(~X{?
M. % p'^5
//等待子线程结束 }( CYok
//int count = 0; M_Q`9
//是否结束while循环 hc[J,yG
boolean breakWhile = false; c*.
Q{?\qCrrYl
Bpm COA
while(!bStop) FU/:'/ L
{ 'W4B
write_nPos(); :aomDK*
Utility.sleep(500); D!! B4zt
breakWhile = true; ?bt;i>O\
j6RV{Lkr_
@&`^#pok
for(int i=0;i<nStartPos.length;i++) }/&Zo=Q$
{ sS;)d
if(!fileSplitterFetch.bDownOver) DbLo{mFEIj
{ yP"}(!~m
breakWhile = false; q~ ZUtF
break; $[?N^
} U5wh( vi
} m"/..&'GC
if(breakWhile) }4!}vkVx
break; !-^oU"
.\T!oSb4[
6vAZLNG3
//count++; m(MQ
//if(count>4) 3N- '{c6]U
// siteStop(); NfPWcK[
} Z!~_#_Ugl
!;h&@LXG(
VgIk'.
System.err.println("文件下载结束！"); M1Ff ,]w
} |8~)3P k
catch(Exception e){e.printStackTrace ();} xWXLk )A
} C]8w[)d[`;
9xz@2b@
(}6\_k[}m
//获得文件长度 ut\X{.r7
public long getFileSize() @@U
{ ukEJD3i
int nFileLength = -1; ><D2of|
try{ f4\$<g/~
URL url = new URL(siteInfoBean.getSSiteURL()); 8Cp@k=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0Zwx3[bq6K
httpConnection.setRequestProperty("User-Agent","NetFox"); M0xhcU_
4]tg!ks
; 8DtnnE
int responseCode=httpConnection.getResponseCode(); h[iO'Vq
if(responseCode>=400) ^gx~{9`RR
{ n/(}|xYU
processErrorCode(responseCode); 3%(r,AD
return -2; //-2 represent access is error aWJ BYw6{L
} aV|VC$
+@!\3a4!
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String sHeader; hx&fV#m
#~/9cVm$
*9r(lmrfj
for(int i=1;;i++) [zN*P$U]
{ %.f%Q?P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2;"vF9WMm
//Utility.log(in.readLine()); lMu9Dp
sHeader=httpConnection.getHeaderFieldKey(i); [<U=)!Swg
if(sHeader!=null) R[l`# I
{ ^j${#Q
if(sHeader.equals("Content-Length")) $dKfUlO
{ 2HBey
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #tHYCSr]
break; IoJI|lP
} zLe(#8G
} +u=VO#IA#
else .hxFFk%5
break; ?'a>?al%>
} \.iejB
} 1+-Go}I
catch(IOException e){e.printStackTrace ();} hy;V~J#
catch(Exception e){e.printStackTrace ();} &F:.V$
Ru#pJb(R
=J)-#|eZG
Utility.log(nFileLength); V6d,}Z+"z'
zL}`7*d:v
l3^'bp6HQ
return nFileLength; $PRd'YdL/
} Q~ Ad{yC
{aV,h@>
e<=Nd,v4;
//保存下载信息（文件指针位置） `u_MdB}<x;
private void write_nPos() TAOsg0
{ VhLfSN>W
try{ Ws0)B8y,|
output = new DataOutputStream(new FileOutputStream(tmpFile)); LqI&1$#
output.writeInt(nStartPos.length); Ws2?sn#x
for(int i=0;i<nStartPos.length;i++) |P& \C8h
{ u@:[ dbJ
// output.writeLong(nPos); 73S N\
output.writeLong(fileSplitterFetch.nStartPos); @N<h`vDa
output.writeLong(fileSplitterFetch.nEndPos); n05GM.|*s
} #+_=(J
output.close(); o-&0_Zq_
} l44QB8 9
catch(IOException e){e.printStackTrace ();} tj*0Y-F~
catch(Exception e){e.printStackTrace ();} Iy;"ht6
} ?5B?P:=kl
|N6.:K[`
t OJyj49^a
//读取保存的下载信息（文件指针位置） 7Q Ns q
private void read_nPos() vN_ 8qzWk
{ ; }T+ImjA
try{ H{i|?a)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RS&BS;
int nCount = input.readInt(); UEx<;P8rP
nStartPos = new long[nCount]; xj8z*fC;
nEndPos = new long[nCount]; &M3KJ I0L
for(int i=0;i<nStartPos.length;i++) #1*7eANfr
{ w8$> 2
nStartPos = input.readLong(); jy>?+hm?
nEndPos = input.readLong(); 9(!AKKrr;
} 0k5uqGLXe
input.close(); 8EdaxeDq
} x3U>5F@
catch(IOException e){e.printStackTrace ();} >/ A'G
catch(Exception e){e.printStackTrace ();} `x>6Wk1
} Pe\Obd8d
/joY? T
,G="wI
private void processErrorCode(int nErrorCode) z6B#F<h
{ o-l-Z|)7
System.err.println("Error Code : " + nErrorCode); 1\aTA,
} (@!K tW
PP!-*~F0Jr
y4IQa.F
//停止文件下载 ?GhMGpdMq
public void siteStop() 0m> 8
{ N`?/kubD
bStop = true; +zLw%WD[l
for(int i=0;i<nStartPos.length;i++) #6D>e~>n
fileSplitterFetch.splitterStop(); !m-`~3P#l,
xw_)~Y%\
FAM:; F30
} -Edy ~;_
} 2&]LZ:(
//负责部分文件的抓取 6`7bk35B
**FileSplitterFetch.java ' i5KRFy-
*/ T!41[vm(
package NetFox; 2.MUQ;OX
.b<W*4{j0H
T2azHo7
import java.io.*; &?1^/]'"r
import java.net.*; Piwox1T;
&)||~
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public class FileSplitterFetch extends Thread { VMJaL}J]
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>!']w{G
String sURL; //File URL +'olC^?5 }
long nStartPos; //File Snippet Start Position SRk!HuXh
long nEndPos; //File Snippet End Position $Q'z9ghEg
int nThreadID; //Thread's ID +0Q +0:
boolean bDownOver = false; //Downing is over vbtZ5Gm
boolean bStop = false; //Stop identical pO:]3qv
FileAccessI fileAccessI = null; //File Access interface z;<~j=lP
Pz:,de~5Qm
G![4K#~NM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException uG6.(A1LM
{ 2?Jw0Wq5D
this.sURL = sURL; </xf4.C
this.nStartPos = nStart; o'(BL:8s
this.nEndPos = nEnd; q6nRk~
nThreadID = id; ?{`7W>G
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +By'6?22
} oxL<\4)WJ
5n}<V-yJ*m
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public void run() H7;,Kr
{ DQXcf*R
while(nStartPos < nEndPos && !bStop) "qR, V9\
{ ,&M#[>\(3
{GnZ@Q:F
.o/uA
try{ vBF9!6X.
URL url = new URL(sURL); `<>QKpAn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *xsBFCRU
httpConnection.setRequestProperty("User-Agent","NetFox"); L;j++^p
String sProperty = "bytes="+nStartPos+"-"; R*lq7n9
httpConnection.setRequestProperty("RANGE",sProperty); N AY3.e
Utility.log(sProperty); @,k5T51m
Gvh"3|u?z
_&S#;ni\c
InputStream input = httpConnection.getInputStream(); <anKw|
//logResponseHead(httpConnection); h ka_Fo
F5/,S
W~D_+[P|_
byte[] b = new byte[1024]; 457{9k
int nRead; I%a-5f$0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xt,Qn460;
{ Q#SQ@oUzD
nStartPos += fileAccessI.write(b,0,nRead); ?-mOAHW0q
//if(nThreadID == 1) SiX<tj#HH\
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \#dacQ2E@
} LAf#Rco4
Sm4BZF~!B
0: hv6Ge^
Utility.log("Thread " + nThreadID + " is over!"); C,l,fT
bDownOver = true; , %z HykP
//nPos = fileAccessI.write (b,0,nRead); (M$>*O3SR
} k"&o)*d
catch(Exception e){e.printStackTrace ();} \b(&-=(
} @g5y_G{SP
} /ugyUpyg
.06D_L"M
~d]v{<3
//打印回应的头信息 pl&nr7\
public void logResponseHead(HttpURLConnection con) ~r8<|$;
{ j;coPehB
for(int i=1;;i++) 9_:"`)]3B
{ #lvt4a"P"
String header=con.getHeaderFieldKey(i); ? F #&F
if(header!=null) A3_p*n@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eP>_CrJb
Utility.log(header+" : "+con.getHeaderField(header)); k B]`py!
else [C6ba{9B
break; 9!Mh(KtQ
} ye$_=KARP
} [%dsq`b#
<5z!0m-G
K}@rte
public void splitterStop() g-d{"ZXd J
{ d%'#-w'
bStop = true; T@yQOD7
} tpcB}HUv
I{(!h90
mk1R~4v
} I&La0g_E
/)_4QSz7
hTn"/|_SW
/* Pqya%j
**FileAccess.java X#$ oV#
*//文件访问(定位，写) @r*GGI!
package NetFox; iLSUz j`
import java.io.*; z U[pn)pe
:wIA.1bK}
U U_0@V<
public class FileAccessI implements Serializable{ u9S*2'
_r3Y$^!U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 n?r8ZDJ'
RandomAccessFile oSavedFile; `S|F\mI~
long nPos; #0<pRDXj
(]'wQ4iQ
)?[7}(4jI
public FileAccessI() throws IOException <h/q^|tZ{
{ {"Sv~L|J;
this("",0); o!UB x<4
} I20~bW
c.]QIIdK
SnFyK5
public FileAccessI(String sName,long nPos) throws IOException o4FHR+u<M
{ <Y"RsW9
oSavedFile = new RandomAccessFile(sName,"rw"); OoA!N-Q
this.nPos = nPos; i_*yS+Z;
oSavedFile.seek(nPos); =_k
} 3 twA5)v
a%`Yz"<lQ
p4z4[=-:
public synchronized int write(byte[] b,int nStart,int nLen) ;?HP/dZLz
{ }cMkh
int n = -1; [x{$f7CEh
try{ G$Mf(S'f
oSavedFile.write(b,nStart,nLen); yGtTD9j
n = nLen; )KFxtM-
} }TMO>eB'
catch(IOException e) xwD`R*
{ 'm*W<
e.printStackTrace (); -hnNaA
} n! 5(Z5=
?=Ceo#Er
#w|v.35%?
return n; .\$A7DD+A
} @*vVc`;
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=|AYT6z,
} %( 7##f_
5;KJ0N*-
#:BkDidt2v
/* 8zeeC eIU
**SiteInfoBean.java ktfm
*/ [r"Oi| 8I
package NetFox; rVP\F{Q4Tr
*CXc{{
=M-=94
public class SiteInfoBean { | U0s1f
?u:`?(\
u_NLgM7*
private String sSiteURL; //Site's URL Y)/|C7~W
private String sFilePath; //Saved File's Path G8vDy1`q6
private String sFileName; //Saved File's Name =cV|o]
private int nSplitter; //Count of Splited Downloading File b}NNkM
g(i6Uj~)
GFLat
public SiteInfoBean() ?l%4 P5
{//nSplitter的缺省值为5 9NwUXh(:(
//default value of nSplitter is 5 nxhlTf>3
this("","","",5); P]n0L4c
} 8>WA5:]v
'i$._Tx
hO[_ _j8
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ojz'p5d`>
{ eEBNO*2
sSiteURL= sURL; _fZec+oM
sFilePath = sPath; b||usv[or
sFileName = sName; 0<v5_pB
this.nSplitter = nSpiltter; +&)/dHbL`]
?3K~4-!?/
b?OA|JqX
} >6yQuB
F%a&|X
!;8Y?c-D
public String getSSiteURL() RuYIG?J=/
{ ZqrS]i@$
return sSiteURL; Q/3*65
} \:Tq0|]Px
A z@@0
x[};x;[ZE
public void setSSiteURL(String value) Nb:j]U
{ ;UgwV/d
sSiteURL = value; a]fFR~OY
} UfPB-EFl$D
G{6@]72
=(hBgNH
public String getSFilePath() X@[5nyILf
{ e0y.J
return sFilePath; ij:a+T
} 9Br+]F_i
]tu OWR
r4[=pfe25
public void setSFilePath(String value) X=-=z5
{ *JX$5bZsI
sFilePath = value; `^{G`es
} Z?xaXFm_
tH;9"z# ~
MkFWZ9c3
public String getSFileName() A@|Z^T:
{ 9~j"6wS
return sFileName; A4(L47^
} l opl
:_i1gY)
[dLc+h1{B
public void setSFileName(String value) t)8crX}P
{ eD7\,}O
sFileName = value; S+KKGi_e
} XsJ`x
fhZwYx&t
0_je@p+$
public int getNSplitter() jA?[*HB
{ i| cA)
return nSplitter; P\WHM(
} #]+BIr`
hb~d4J=S
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public void setNSplitter(int nCount) ,[p?u']yZz
{ hU(
nSplitter = nCount; < q(i(%
} bZWR.</
} E l.eK9L
!V#*(_+n
pvt/{
/* R-n%3oh
**Utility.java Kg2@]J9m
*/ QP<P,Bi~
package NetFox; |af<2(d
p({|=+bl
vr47PM2al
public class Utility { ~qb?#IY]`
E.$//P n|1
056yhB
public Utility() ]lJ#|zd8o
{ /-<]v3J
=#TQXm']Gi
ocW`sE?EED
} Rbm+V{EF&
zXGI{P0O
//线程睡眠 3S^Qo9S
public static void sleep(int nSecond) c?xeBC1-
{ 3s:)CXO
try{ hhjsg?4uL
Thread.sleep(nSecond); .*FlB>1jy
} IP !zg|c,
catch(Exception e) uTbMp~cYB
{ $\4Or
e.printStackTrace (); ~c1~)QzZ
} ,,9vk\
} 3kJSz-_M
)Knsy
//日志 #2.C$
public static void log(String sMsg) z9#jXC#OdN
{ 0Z%<H\Z
System.err.println(sMsg); y;9K
} . 55aY~We
@izS_I,
a~tBgy+9
public static void log(int sMsg) 4f0dc\$
{ kr1^`>O5
System.err.println(sMsg); yNx"Ey dk`
} @qJv
} +fIyeX
&P8Q|A-u
.fW`/BXE
/* `+r5I5
**TestMethod.java Z3T26Uk
*/ yFP#z5G
package NetFox; D3 E!jQ1
VHws9)
|@)ij c4i
public class TestMethod { !lB,2_
`V0]t_*D
==j39
public TestMethod() t!Av[K
{ ///xx/weblogic60b2_win.exe BQ&h&57K
try{ 9zd)[4%=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IPE(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 17qrBG-/MD
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9p$q@Bc
fileFetch.start(); Bp6Evi
} #wm)e)2@
catch(Exception e){e.printStackTrace ();} ZNA?`Z)f
Ap>n4~
86} rz
} aA yFu_
Ip1QmP
n:!J3pR
public static void main(String[] args) CC87<>V
{ q{JD]A:
new TestMethod(); 3i$AR
} {S&&X&A`v
} 3 \WdA$Wx
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