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)); L`YnrDZK
} .Lo$uKsW$l
for(int i=0;i<nEndPos.length-1;i++) I]>-~_
{ YH^_d3A;
nEndPos = nStartPos[i+1]; 4@|K^nT`
} -vI?b#
nEndPos[nEndPos.length-1] = nFileLength; $=$I^hV
} Z9ciS";L
} v@;:aN
PGMu6$
C8cB Lsa[J
//启动子线程 D5)qmu
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;h_"5/#
for(int i=0;i<nStartPos.length;i++) mSAuS)YD
{ 8Uvf9,I'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #6_?7 (X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MC/$:PV
nStartPos,nEndPos,i); sMli!u
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y-}lz#N
fileSplitterFetch.start(); 2GcQh]ohc
} YL&$cT]1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), it\{#rb=4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a=k+:=%y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XZuJ<]}X,
nEndPos = " + nFileLength); a=gTGG"9
// fileSplitterFetch[nPos.length-1].start(); &Z5$ 5,[
0G9@A8LU
Giz9jzF\
//等待子线程结束 *#Hi W)
//int count = 0; ]c+qD,wqt>
//是否结束while循环 <"/Y`/
boolean breakWhile = false; E8=.TM]L
%p"x|e
A$A7F=x
while(!bStop) oo3ZYA
{ x2/|i?ZO
write_nPos(); jDcE_55o
Utility.sleep(500); ;=hl!CB
breakWhile = true; N{iBVl
7*OO k"9
5JDqSz{
for(int i=0;i<nStartPos.length;i++) =ALy.^J=
{ ][:6En}
if(!fileSplitterFetch.bDownOver) _x z_D12
{ E3.=|]W'
breakWhile = false; }f^r@3Cb3
break; eGvHU ;@
} QY-P!JD
} >Fz_]z
if(breakWhile) NaG1j+LN
break; ZP*Hx %U
v*QobI
z]Z>+|
//count++; 1QE-[|
//if(count>4) l},*^Sn<5
// siteStop(); dnNC = siY
} d#I'9O0&
B[C2uVEX:
zrU0YHmt
System.err.println("文件下载结束！"); q+dY&4&u
} 6,uW{l8L
catch(Exception e){e.printStackTrace ();} s[h'W~
} }@4m@_gR?
}0?642 =-
j)C%zzBu(
//获得文件长度 <|Bh;;
public long getFileSize() O9A.WSJ >}
{ }{:H0)H*
int nFileLength = -1; f&H):.
try{ X~5TA)h;~
URL url = new URL(siteInfoBean.getSSiteURL()); m}]"TFzoVM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h -+vM9j
httpConnection.setRequestProperty("User-Agent","NetFox"); !zvKl;yT
;_of'
waQNX7Xdn
int responseCode=httpConnection.getResponseCode(); }Nl-3I.S^
if(responseCode>=400) E92dSLhs5
{ +kH*BhSj
processErrorCode(responseCode); ;QW6Tgt11
return -2; //-2 represent access is error qUx!-DMY
} ep3_G\m
N|z-s
joAR;J
String sHeader; eek5Xm
>6=yxCJ
fa/ '4
for(int i=1;;i++) WY?(C@>s
{ D._q'v<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8G1Tpn
//Utility.log(in.readLine()); K`j#'`/KC
sHeader=httpConnection.getHeaderFieldKey(i); Yj/S(4(h?
if(sHeader!=null) #_QvnQ?I
{ KZ`d3ad
if(sHeader.equals("Content-Length")) {_ww1'|A
{ EHcqj;@m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]$4k+)6
break; %K;,qS'N_
} aIRCz=N
} * ?rw'
else b,~4O~z
break; ToCB*GlL
} wP6~HiC
} $oH?oD1
catch(IOException e){e.printStackTrace ();} bh6Mh<+
catch(Exception e){e.printStackTrace ();} g/mVd;#o
Up*p*(d3
q3VE\&*^F
Utility.log(nFileLength); OlRBvfoh8
7cr+a4T33
T}$1<^NK
return nFileLength; tKo^A:M
} @GBS-iT3
C"<l}
4.|]R8Mn
//保存下载信息（文件指针位置） I`t"Na2i
private void write_nPos() [O&2!x
{ pxM^|?Hxc
try{ "|]'\4UdzQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2!-ZNd:(+
output.writeInt(nStartPos.length); |5Mhrb4.
for(int i=0;i<nStartPos.length;i++) 3:YZC9
{ R8c1~'
// output.writeLong(nPos); :v* _Ay
output.writeLong(fileSplitterFetch.nStartPos); Ol~sCr
output.writeLong(fileSplitterFetch.nEndPos); vE>J@g2#
} +Ys<V
output.close(); ?c+_}ja,
} /wKW
catch(IOException e){e.printStackTrace ();} Aw;~b&.U{_
catch(Exception e){e.printStackTrace ();} gZM\RJZ_
} SM@l4GH
x5WFPY$wM
I6M 7xn
//读取保存的下载信息（文件指针位置） GW ?.b_6*
private void read_nPos() *["9;_KD
{ 3K@dW"3
try{ UVUbxFq:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !Jh-v
int nCount = input.readInt(); G>M# BuU
nStartPos = new long[nCount]; Vu*yEF}
nEndPos = new long[nCount]; &AU%3b
for(int i=0;i<nStartPos.length;i++) `*&*jdq&i
{ PnFU{N
nStartPos = input.readLong(); Nw+0b4{
nEndPos = input.readLong(); S?D|"#-,
} pez[qs
input.close(); 6U @3 xU`
} zKx?cEpE
catch(IOException e){e.printStackTrace ();} kmi[u8iXD_
catch(Exception e){e.printStackTrace ();} (VO) Q
} w_ kHy_)
IwZn%>1N
e/6WhFN#
private void processErrorCode(int nErrorCode) @rRBo:0%
{ ]sd|u[:k
System.err.println("Error Code : " + nErrorCode); d?oupW}uu
} 1C{n!l
ivb&J4?y
2rB$&>}T
//停止文件下载 gLsl/G
public void siteStop() zg.'
{ Kg VLXI6
bStop = true; oA(jtX[(
for(int i=0;i<nStartPos.length;i++) c;xL.
fileSplitterFetch.splitterStop(); Tt`|26/
x4CrWm
J*-m!0 5
} L oe!@c
} o*_[3{FU
//负责部分文件的抓取 ^W eE%"
**FileSplitterFetch.java al F*L
*/ f+}?$'
package NetFox; 6;dQ#wmg
`l9Pk\X[
s_hf,QH
import java.io.*; 0F8y8s
import java.net.*; }W#Gf.$6C
kUUN2
E b-?wzh
public class FileSplitterFetch extends Thread { MG*#-<OV.
^+F@KXnL
we4e>)
String sURL; //File URL Sqed*
long nStartPos; //File Snippet Start Position Lp5LRw
long nEndPos; //File Snippet End Position >to NGGU=~
int nThreadID; //Thread's ID [<}:b>a
boolean bDownOver = false; //Downing is over :UoZ`O~
boolean bStop = false; //Stop identical vDV`!JU
FileAccessI fileAccessI = null; //File Access interface }N]|zCEj
G!RbM.6
:@y!5[88!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Fx0E4\-
{ M n`gd#
this.sURL = sURL; MRxzOs
this.nStartPos = nStart; sTP`xaY
this.nEndPos = nEnd; >2x[ub%$L
nThreadID = id; Gw:8-bxS
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7"yA~e,l
} skh6L!6*<
a9j f7r1
w=vK{h#8
public void run() ?[hIv6c
{ +;c)GNQ)6:
while(nStartPos < nEndPos && !bStop) H{VVxj
{ .}&bE1
w= |).qQ]
hD/bgquT
try{ -%E+Yl{v
URL url = new URL(sURL); y))d[1E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 0UB)FK,9
httpConnection.setRequestProperty("User-Agent","NetFox"); %"r3{Hs
String sProperty = "bytes="+nStartPos+"-"; z4!TK ps
httpConnection.setRequestProperty("RANGE",sProperty); ?x7zYE,6
Utility.log(sProperty); =H%c/Jty
o9(:m
'`p#%I@
InputStream input = httpConnection.getInputStream(); x9bfH1
//logResponseHead(httpConnection); St7ZyN1
$ jWe!]ASU
8)\TdtBf9
byte[] b = new byte[1024]; *v 1hMk
int nRead; u27K 0}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O68/Hf1W
{ ,j>A[e&.
nStartPos += fileAccessI.write(b,0,nRead); 3.Z}2F]
//if(nThreadID == 1) @d:TAwOI'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #!wu}nDu
} qPDe;$J)
}enm#0Ha
PN:/lIO
Utility.log("Thread " + nThreadID + " is over!"); H:Y?("k
bDownOver = true; @W[`^jfQ
//nPos = fileAccessI.write (b,0,nRead); f]W$4f{
} |=fa`8mG
catch(Exception e){e.printStackTrace ();} _CN5,mLNRk
} 15U]/?jv8
} ZX[@P?A+-
/Fy2ZYs,`8
b-ZC~#?|b
//打印回应的头信息 ^&F8NEb=2>
public void logResponseHead(HttpURLConnection con) h)fJ2]JW8W
{ fQ33J>
for(int i=1;;i++) `n7*6l<k~4
{ .xo#rt9_"=
String header=con.getHeaderFieldKey(i); LfOXgn\
if(header!=null) B*!{LjXV
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o9&1Ct
Utility.log(header+" : "+con.getHeaderField(header)); hC2@Gq
else ! eXDN
break; LlOUK2tZ
} 8MqKS}\H
} D@A@5pvS
`1k0wT(
,7-@eZ
public void splitterStop() r#hA kOw
{ OZ##x
bStop = true; ,'w9@A
} %ub\+~
f|Dq#(^\
HjCcfOej
} p?F%a;V3
t M?3oO
:j feY
/* _]zm02|
**FileAccess.java z0|%h?N
*//文件访问(定位，写) 'b(V8x
package NetFox; KYBoGCS>
import java.io.*; FbO\#p s
h[HFZv~{
_voU^-
public class FileAccessI implements Serializable{ 21ng94mC
0 ~K4vSa
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |uL"/cMW7
RandomAccessFile oSavedFile; :+Ti^FF`w
long nPos; r0jhIE#
{}x{OP
~Y;_vU
public FileAccessI() throws IOException "A?&`}%
{ K6 D3
this("",0); 86+nFk
} qcpAjjK
a2Q_K2t
4FLL*LCNX
public FileAccessI(String sName,long nPos) throws IOException (NB\wJg $
{ G_OLUuK?C
oSavedFile = new RandomAccessFile(sName,"rw"); (.[HE ~ s?
this.nPos = nPos; U&x)Q
oSavedFile.seek(nPos); ^q{=mf`
} KlOL5"3
Sy\ec{$+V]
o&-c5X4
public synchronized int write(byte[] b,int nStart,int nLen) =XAFW
{ HYqDaRn
int n = -1; lO)-QE+
try{ 3hUU$|^4gm
oSavedFile.write(b,nStart,nLen); ]H[%PQ r`Z
n = nLen; :x*#RnRr.
} U42B(ow
catch(IOException e) eD<Kk 4){
{ -bJC+Yn
e.printStackTrace (); \M(#FS
} Q--Hf$D]H
iH&BhbRu_
.MUoNk!
return n; ..u2IdEu
} gFBMARxi
7Qoy~=E
a@mMa {
} 3/d`s0O
$K-od3h4=
r*Iu6
/* g+ZQ6Hz
**SiteInfoBean.java 4\Nt"#U)g
*/ h4N%(?7
package NetFox; Pgdv)i3
BZUA/;Hz &
&n 1 \^:
public class SiteInfoBean { $)(K7> P
ItLP&S=
LA\)B"{J
private String sSiteURL; //Site's URL fwWE`BB
private String sFilePath; //Saved File's Path j)A$%xUo
private String sFileName; //Saved File's Name vJ`'x
private int nSplitter; //Count of Splited Downloading File b!do7%]i
`y%1K|Y=
fQ.{sQ$@h
public SiteInfoBean() cx_.+R
{//nSplitter的缺省值为5 aNcuT,=(?8
//default value of nSplitter is 5 estDW1i)
this("","","",5); Qx{[#[Da
} (=de#wh2]
w26x)(7
v8PH(d2{@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ~4MUac^w
{ Vy+UOV&v-
sSiteURL= sURL; zLeId83>
sFilePath = sPath; (K"8kQLY
sFileName = sName; DnY7$']"|
this.nSplitter = nSpiltter; BkO)hze
-( d,AX
M?yWFqFt9m
} ? FlV<nE"J
h_w_OCC&2
zc,kHO|
public String getSSiteURL() Td6Gu"
{ gp?|UMA9.
return sSiteURL; _mi(:s(
} Xfq]vQ/{
]n/fB|tE
l>H G|ol
public void setSSiteURL(String value) 4t Z. T9d
{ Wd0$t
sSiteURL = value; #!h +K"wX
} Y64B"J=P9
x?|C-v
P0/B!8x
public String getSFilePath() *,Mg
{ Xy;!Q`h(
return sFilePath; Z T5p
} NbDfD3 1GK
G0u3*.
s</llJ$
public void setSFilePath(String value) -_>g=a@&
{ Qey6E9eCA
sFilePath = value; DJm/:td
} tG{?
x:Nd>Fb
WecJ^{g>r{
public String getSFileName() *C0gpEf9S
{ CYxrKW l:'
return sFileName; SdI/
} 7+h*&f3>
wn$:L9"YN
4-YXXi}
public void setSFileName(String value) c=-2c&=&
{ q|8p4X}/]
sFileName = value; "eH~/6A
} c/c%-=
te+5@k#t
CCX!>k]
public int getNSplitter() a%wK[yVp
{ {]a 6o[}u
return nSplitter; h0N*hx
} jJ' LM>e
? 77ye
M~G1ZB
public void setNSplitter(int nCount) SwDUg}M~
{ {mlJE>~%
nSplitter = nCount; i>M*ubWE4@
} ? }k~>. \
} 7 -(LWH
YS_9M Pi
<IF\;,.c
/* jZ'y_
**Utility.java <N{pMz
*/ iZ`1Dzxgk
package NetFox; us.+nnd
N1V qK
|sw&sfH[FD
public class Utility { AR}M*sSh
`B`/8Cvg
:*2+t-
public Utility() l;e&p${P
{ lRn6Zh
v!;E1
t `4^cd5V
} d E@R7yU@
9iQcK&D 2
//线程睡眠 RfT#kh/5
public static void sleep(int nSecond) h&!k!Su3#
{ "~h.u
try{ V.IgEE]
Thread.sleep(nSecond); ,x+_/kqx
} ax0:v!,e
catch(Exception e) |U_48
{ y\ nR0m
e.printStackTrace (); C { }s
} 4*UoTE-g$
} ifu"e_^
l|-TGjsX
//日志 X7sWu{n
public static void log(String sMsg) tPS.r.0#^
{ MwxfTH"wi
System.err.println(sMsg); z]k=sk
} Ne]/ sQ0
{-rK:*yP'u
-=E/_c;
public static void log(int sMsg) yG0Wr=/<?
{ .P=uR8
System.err.println(sMsg); ?lxI& h
} eiZv|?^0
} auP:r
i3.8m=>
[Cz.K?+#M
/* ~Exd_c9
**TestMethod.java 1Tn!.E *
*/ E<3hy
package NetFox; 3zb;q@JV
y+RT[*bX5o
VI%879Z\e
public class TestMethod { /Q"nQSG
s)HbBt-
o'Q)V
public TestMethod() ^zGgvFf>
{ ///xx/weblogic60b2_win.exe "7!K'i
try{ |}*k|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %E7+W{?*1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )o[ O%b
SiteFileFetch fileFetch = new SiteFileFetch(bean); h<*l=`#
fileFetch.start(); xZ@H{):
} f8! PeQ?
catch(Exception e){e.printStackTrace ();} @A6\v+ih
&Ko}Pv
1fL@rR
} FTt7o'U
DR9M8E
M[_~7~4
public static void main(String[] args) xIF z@9+k
{ RlX;c!K
new TestMethod(); GI$t8{M
} ',0~\V
} vjJ!d#8
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