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)); r{Fu|aoa;5
} s'5 jvlG
for(int i=0;i<nEndPos.length-1;i++) $]%k <|X
{ Kk??}
nEndPos = nStartPos[i+1]; FiFZM
} 1bvL
nEndPos[nEndPos.length-1] = nFileLength; dn`#N^Od
} Y4b"(ZhM_
} ~[,E i k
9Uk9TG5
12k)Ek9
//启动子线程 g[Yok`e[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; oTfEX4 t {
for(int i=0;i<nStartPos.length;i++) n){\KIU/O
{ ,@>B#%Nz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?DpMR/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G%4vZPA
nStartPos,nEndPos,i); cvc.-7IO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); G.(9I~!
fileSplitterFetch.start(); =>BT]WK>
} oR3$A :!P=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *Jp>)>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5@Rf]'1B0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", wdp4-*
nEndPos = " + nFileLength); &Cdd
// fileSplitterFetch[nPos.length-1].start(); 7Qq>?H -
HK ;C*;vC%
=I*"vwc?
//等待子线程结束 zJ@f {RWZa
//int count = 0; ..n-&(c32
//是否结束while循环 xx41Qw>\W
boolean breakWhile = false; >\VZ9bP<
6Lz&"C,`
!q$IB?8
while(!bStop) m~X:KwK4
{ R=PjLH&)
write_nPos(); w`i3B@w
Utility.sleep(500); (+T|B E3*#
breakWhile = true; TNiFl hq
^8We}bs-c
(\SxG\`
for(int i=0;i<nStartPos.length;i++) o<%Sr*
{ ,wnF]K2D0
if(!fileSplitterFetch.bDownOver) Ee4oTU5Mb
{ =FdS'<GM
breakWhile = false; `bivAL
break; a*??!
} (8{h I
} w'cZ\<N[
if(breakWhile) ~2=B:;
break; Fet>KacTht
&o)j@5Y?
[?]s((A~B
//count++; }X}fX#[
//if(count>4) a}%>i~v<
// siteStop(); -S9$C*t
} B \[P/AC
z^=9%tLJ
6kYn5:BhIi
System.err.println("文件下载结束！"); 4.R >mN[
} e'g-mRh
catch(Exception e){e.printStackTrace ();} v')T^b F@
} wYNh0QlBH
W!+5}\?
/|hKZTZJdN
//获得文件长度 -YRF^72+
public long getFileSize() lwjg57
{ `"/@LUso
int nFileLength = -1; dp-8,Seu
try{ Hz+edMUL
URL url = new URL(siteInfoBean.getSSiteURL()); "4i(5|whp?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C#vU'RNpl
httpConnection.setRequestProperty("User-Agent","NetFox"); H?^Poe(=(
CCQ<.iCU
LLV:E{`p
int responseCode=httpConnection.getResponseCode(); m<TKy_C`
if(responseCode>=400) ={8ClUV#
{ QnVYZUgJeV
processErrorCode(responseCode); r!j_KiUy
return -2; //-2 represent access is error m$0T"`AP`
} -:>Mi5/ s
=][[TH
+>37'PD
String sHeader; 1;g>?18@
'}]w=2Lf
&P,8)YA
for(int i=1;;i++) O`Nzn~),x
{ yj"+!g
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YDdmT7Ow
//Utility.log(in.readLine()); ocGqXDg3
sHeader=httpConnection.getHeaderFieldKey(i); rS8/_'
if(sHeader!=null) F0]NtKaH
{ .kGg}
if(sHeader.equals("Content-Length")) jh2D9h
{ w}YO+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ;NBJ@E,
break; #tGW|F
} @My-O@C>
} `epO/Uu\~u
else E<D45C{DP
break; c$bb0J%
} K'Bq@6@C g
} DMsxHAE1
catch(IOException e){e.printStackTrace ();} VuPa'2
catch(Exception e){e.printStackTrace ();} ,o*x\jrGw
~bg?V0
DXsp 2
Utility.log(nFileLength); gb(a`
Mb"i}Yt{
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return nFileLength; S:+SZq
} yiWBIJ2Wu9
$0+AR)
OZB(4{vnyC
//保存下载信息（文件指针位置） 6"/cz~h
private void write_nPos() ^fQ ]>/u
{ n&pi
try{ mi`!'If0)
output = new DataOutputStream(new FileOutputStream(tmpFile)); 48Vmz
output.writeInt(nStartPos.length); 'n6D3Vse
for(int i=0;i<nStartPos.length;i++) ;r B2Q H]
{ dpxP
// output.writeLong(nPos); ,W'`rCxJ
output.writeLong(fileSplitterFetch.nStartPos); f]jAa?d T&
output.writeLong(fileSplitterFetch.nEndPos); JS1$l+1
} ~Uz,%zU#3
output.close(); @6~r7/WD
} &$:1rA_v
catch(IOException e){e.printStackTrace ();} " ;8H;U`
catch(Exception e){e.printStackTrace ();} |$f.Qs~?
} -hZlFAZi
:D\M.A
D C{l.a.
//读取保存的下载信息（文件指针位置） @!1o +x
private void read_nPos() z'z_6]5
{ ]+u`E
try{ [AstD9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2f2Vy:&O_
int nCount = input.readInt(); p2cwW/^V
nStartPos = new long[nCount]; lyc ]E 9
nEndPos = new long[nCount]; k)U9%Pr
for(int i=0;i<nStartPos.length;i++) omisfu_~E
{ 4^/MDM@
nStartPos = input.readLong(); j*B,b4
nEndPos = input.readLong(); __dSEOGoe
} HRS^91aK
input.close(); dT?/9JIv
} b*i_'k}*<g
catch(IOException e){e.printStackTrace ();} )zzZYs&|
catch(Exception e){e.printStackTrace ();} j?<>y/IR
} l.[S.@\=.
I.As{0cc
}#]2u|G
private void processErrorCode(int nErrorCode) <]1Z
{ <Ih)h$8`
System.err.println("Error Code : " + nErrorCode); 6AD#x7drj
} #29m <f_n
rWsUWA T*
=]i[gs)B
//停止文件下载 @#m@ .
public void siteStop() di$\\ Ah
{ :E`/z@I
bStop = true; O1]L4V1iH
for(int i=0;i<nStartPos.length;i++) >d2U=Yk!
fileSplitterFetch.splitterStop(); *f<+yF{=A
T)4pLN E
r Z)?uqa
} ~nLE?>x|Z
} jMFLd
//负责部分文件的抓取 noI>Fw<V
**FileSplitterFetch.java Ilf;Q(*$>>
*/ uknX py))
package NetFox; SWwL.-+E]
]c/k%]o~
55LW[Pc
import java.io.*; XM?>#^nC?u
import java.net.*; EGJ d:>k
!C]2:+z-MF
&=ZVU\o:
public class FileSplitterFetch extends Thread { )c432).Z
LKC^Y)6o
_TLB1T^/4
String sURL; //File URL vT1StOx<V
long nStartPos; //File Snippet Start Position d-k`DJ!
long nEndPos; //File Snippet End Position TjDDvXY
int nThreadID; //Thread's ID Vd%%lv{v
boolean bDownOver = false; //Downing is over 7# !RX3
boolean bStop = false; //Stop identical Q6qIx=c4
FileAccessI fileAccessI = null; //File Access interface ) oypl+y
ut/3?E1 Z
]]"O)tWHj
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %mF:nU4
{ k{Ad(S4J&
this.sURL = sURL; SHcFnxEAIH
this.nStartPos = nStart; STln_'DF'
this.nEndPos = nEnd; OS- Xh-:z
nThreadID = id; tRC*@>I$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t,P_&0X
} ZsnFuk#W
-6KNMk
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public void run() O%m\ Q1
{ u$M,&Om
while(nStartPos < nEndPos && !bStop) Mn>/\e
{ nXRT%[o&
?Sj>b
b@s6jNhVO^
try{ L|hoA9/]
URL url = new URL(sURL); (8Ptuh6\\2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .m gm1zz
httpConnection.setRequestProperty("User-Agent","NetFox"); /BN_K8nb`
String sProperty = "bytes="+nStartPos+"-"; Ez)hArxns
httpConnection.setRequestProperty("RANGE",sProperty); XK+" x!
Utility.log(sProperty); _A/q bm
VY1&YR}Y
yw@kh^L
InputStream input = httpConnection.getInputStream(); *r90IS}A$2
//logResponseHead(httpConnection); V9:Jz Q=?`
x9!3i{_
>))f;$D=
byte[] b = new byte[1024]; C0`Bi:Ze
int nRead; :HiAjaA1pg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;07>ZH%
{ (/qOY
nStartPos += fileAccessI.write(b,0,nRead); ;}>g/lw
//if(nThreadID == 1) hj4mbL
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "ZYdJHM
} gVscdg5
Ip_deP@
d8C44q+ds
Utility.log("Thread " + nThreadID + " is over!"); `qs[a}%'>"
bDownOver = true; qG)M8xk
//nPos = fileAccessI.write (b,0,nRead); ABaK60.O[O
} "h`oT4j5q
catch(Exception e){e.printStackTrace ();} :3N&&]
} a\l?7Jr
} 8\BGL
eYQPK?jo
I6e[K(7NY
//打印回应的头信息 CK=TD`$w
public void logResponseHead(HttpURLConnection con) ;R[w}#Sm
{ ascY E
for(int i=1;;i++) q).["fSV
{ /?Y]wY
String header=con.getHeaderFieldKey(i); <zWMTVaC
if(header!=null) q@=3`yQ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3YO%$
Utility.log(header+" : "+con.getHeaderField(header)); dTrz7ayH
else 4K(oOxc9.
break; `i5\(cdl
} -]. a0
} Q)[DSM
IY"+hHt
vrq5 +K&||
public void splitterStop() HD_ #-M
{ HT%'dZ1
bStop = true; =1r!'<"h
} B{tROuN<
:\F1S:&P
,^1B"#0{C<
} ?#~km0~F)
up!54}qy
-T=sY/O
/* OPuty/^!Gw
**FileAccess.java KXf(v4
*//文件访问(定位，写) Zg&o][T
package NetFox; jB"IJ$cD
import java.io.*; n@$("p
J3QL%#
mW=9WV
public class FileAccessI implements Serializable{ LsxRK5
!~Ptnr`;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (91 YHhk{
RandomAccessFile oSavedFile; 0dW*].Gi:
long nPos; GS&I6
QV[#^1
qM18Ji*
public FileAccessI() throws IOException lOy1vw'
{ aQ*?L l
this("",0); |,Kk#`lW<f
} ^{Fo,7
: "^/?Sd
]^53Qbrv
public FileAccessI(String sName,long nPos) throws IOException 8o i{%C&-
{ LeV";=_n
oSavedFile = new RandomAccessFile(sName,"rw"); TSTkMlCG
this.nPos = nPos; _0|@B8!J?
oSavedFile.seek(nPos); QlMv_|`9
} 4Opf[3]
az[#q
z&Xk~R*$
public synchronized int write(byte[] b,int nStart,int nLen) BA8g[TA7K
{ 9qkJ<
int n = -1; Y|6gg
try{ qVW3oj<2
oSavedFile.write(b,nStart,nLen); ;}H*|"z;!
n = nLen; A|(!\J0
} jqlfypU
catch(IOException e) b}&.IJ&40j
{ Q`!^EyRA:^
e.printStackTrace (); .@0@Y
} T"3:dkQw
I;9C":'#
}wZsM[NDB
return n; AC*SmQ\>!
} D*/fY=gK
I9e3-2THfj
"R\D:Olb#
} OX7a72z
+4+czfz
TBZhL
/* R*?!xDJ
**SiteInfoBean.java @RZbo@{~
*/ i|rCGa0}
package NetFox; z31g"
2sj: &][R
07]9VJa
public class SiteInfoBean { Pk;1q?tGw
}`aT=_B
-jzoGzC3
private String sSiteURL; //Site's URL N cp
private String sFilePath; //Saved File's Path <'48mip
private String sFileName; //Saved File's Name #qARcxbK|
private int nSplitter; //Count of Splited Downloading File Z<*"sFpAO
X]D:vuB
'nS>'yYH#
public SiteInfoBean() 2FY]o~@
{//nSplitter的缺省值为5 p +nh]
//default value of nSplitter is 5 +6x}yc:yd
this("","","",5); G#~U\QlG-
} $b[Ha{9(v
] &SmeTe
Tz~a. h@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hj\A-Yf
{ 4aKppj
sSiteURL= sURL; X3][C
sFilePath = sPath; =?_:h`}
sFileName = sName; `dWnu3r;
this.nSplitter = nSpiltter; p(cnSvg
I%b5a`7
x=-(p}0o;<
} 96S$Y~G#&
"Th;YJu
[E+J=L.l
public String getSSiteURL() ?mF:L"i
{ fQ1Dp
return sSiteURL; W*?qOq {
} <9\Lv]ng
i(ZzE
B)/c]"@89
public void setSSiteURL(String value) J*_^~t
{ \6bvk_
sSiteURL = value; 6@"E*-z$
} AAqfp/DC
=nO:R,U
[e_<UF@A*
public String getSFilePath() %zo 6A1Q;
{ =$%-RX7
return sFilePath; Qn~{TZz
} [XH,~JZJj
WYP\J1sy
#s' `bF^
public void setSFilePath(String value) F+?i{$
{ C,%Dp0
sFilePath = value; -8vGvI>
} @BPQ >
H=w6
CEBu[TT/9
public String getSFileName() w `+.F;}s
{ 4.Fh4Y:$'
return sFileName; 7HQL^Q
} 4E_u.tJ
feH&Ug4?G
[k75+#'
public void setSFileName(String value) {U@"]{3Qx
{ 8k)*f+1o
sFileName = value; .tHjGx
} _\8E/4zh
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X$G:3uoN
public int getNSplitter() p!)PbSw#
{ XH0o8\.
return nSplitter; 1f1D^|
} v~W;&{
*_mER`
<%W&xk
public void setNSplitter(int nCount) MiKq|
{ ^UhqV"[7k
nSplitter = nCount; f`K#=_Kq7
} L>&{<M_
} XMykUr e|
L?P[{Ohh/
Fp"c {
/* ;j[gE
**Utility.java |}:q@]dC#
*/ X+HPdrT
package NetFox; F&^&"(H}
:oYSvK7>
@3 +
public class Utility { 9eE FX7
?B)e8i<[f
,1-idpnX
public Utility() DHyQ:0q
{ \d:Uq5d)0
\}<J>R@
0r[a$p>`
} 0"N4WH O
cG3tn&AXi
//线程睡眠 ,%zE>^~
public static void sleep(int nSecond) {j<?+o5A
{ N6T
try{ 4x=sJ%E
Thread.sleep(nSecond); |mdf u=
} |5q,%9_
catch(Exception e) /qq*"R
{ %U.x9UL
e.printStackTrace (); 9x(t"VPuS
} KV'3\`v@LY
} &uV|Ie8@q
{ i4`-w
//日志 (JE&1 @
public static void log(String sMsg) MCIuP`sC|
{ -]YsiE?r
System.err.println(sMsg); Q84XmXm|
} pN)>c,
C\;%IGn
&N3a`Ua
public static void log(int sMsg) qC=ZH#
{ e(OKE7
System.err.println(sMsg); _g D9oK
} F4~O-g.<
} B{S^t\T$
B4c;/W-
&Ot9"Aq:
/* ?i!d00X
**TestMethod.java x #|t#N%
*/ Xg;<?g?k
package NetFox; ,wHlU-%
5l(@p7_+
eSW}H_3
public class TestMethod { <K/iX%b?
S3QX{5t\
@)z?i
public TestMethod() dWo$5Bls<A
{ ///xx/weblogic60b2_win.exe - s{&_]A~
try{ 62[_u]<Yub
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $z5C+K@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mVK^gJ3
SiteFileFetch fileFetch = new SiteFileFetch(bean); K!-iDaVI
fileFetch.start(); Y]B9*^d<
} <BBSC
catch(Exception e){e.printStackTrace ();} K8QEHc:
%T;VS-f
bZ+Hu~
} em ]0^otM
I=YZ!*f/`
1vqc8lC
public static void main(String[] args) :&RpB^]
{ 4]%MrSjS
new TestMethod(); uL~.#Y_jQ
} 6Q*zZ]kg
} nv:VX{%
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