http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); mQJGKh&Pk
} dGjvSK<1@
for(int i=0;i<nEndPos.length-1;i++) b L~<~gA
{ eyV904<F
nEndPos = nStartPos[i+1]; qsx1:Ny1
} ktRdf6:~
nEndPos[nEndPos.length-1] = nFileLength; VVY\W!
} \ 3N#%
} 3iTjM>+>
4F?1,-X
oY:>pxSz<@
//启动子线程 [Ma9
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]W,g>91m
for(int i=0;i<nStartPos.length;i++) ) |a5Qxz
{ Vy$\.2=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u:$x,Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `R^VK-=C
nStartPos,nEndPos,i); uv!/DX#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0:EiCKb)ol
fileSplitterFetch.start(); K9=_}lS@'
} )9O{4PbU!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %e(,PL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7 &Aakl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", EzaOg|
nEndPos = " + nFileLength); uPPe"$
// fileSplitterFetch[nPos.length-1].start(); gu!A:Q
^y,ip=<5\3
-_(!
//等待子线程结束 zO,sq%vQn'
//int count = 0; /^"TMm
//是否结束while循环 hAdEq$
boolean breakWhile = false; *RO ~%g
[A47OR
sh1fz 6g
while(!bStop) j06DP _9M
{ ?}.(k/
write_nPos(); {U9jA_XX
Utility.sleep(500); Df9}YI;?
breakWhile = true; -~g3?!+Hb
;DTNw=
<Jx{Uv
for(int i=0;i<nStartPos.length;i++) "O`;zC
{ ?W(f%/B#
if(!fileSplitterFetch.bDownOver) yLP0w^Q
{ M<729M
breakWhile = false; IP3-lru
break; yY+2;`CH
} 6-~
} "?!IPX2\S
if(breakWhile) b8Qm4b?:4
break; tj0vB]c
6yU~^))bx
#LZ`kSlv4
//count++; = N#WwNC
//if(count>4) j.K yPWO
// siteStop(); !Zrvko
} @fwU%S[v
,F[mh
y-U(`{[nM
System.err.println("文件下载结束！"); #3S/TBy,
} yRtFUlm`
catch(Exception e){e.printStackTrace ();} ]8#{rQ(
} }y1M0^M-$
'coqm8V[%
yQ}~ aA#h
//获得文件长度 @l8?\^N
public long getFileSize() 1#V0g Q
{ [|YMnV<B
int nFileLength = -1; z(ajR*\#
try{ B@4#y9`5
URL url = new URL(siteInfoBean.getSSiteURL()); E_OLf%um
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x[X.// :
httpConnection.setRequestProperty("User-Agent","NetFox"); xfzR>NU
u0,~pJvX
`'>>[*06:a
int responseCode=httpConnection.getResponseCode(); WXM_H0K
if(responseCode>=400) #df43_u
{ YW5E |z
processErrorCode(responseCode); /X?Nv^Hy
return -2; //-2 represent access is error Wi[Y@
} ru&RL HFV
;KhYh S(q
-nW{$&5AF
String sHeader; lbPxZ'YO#
mH?hzxa+
xU&rUk/L
for(int i=1;;i++) @ZVc!5J_,
{ 17GyE=Uu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Xk3Ufz]QN
//Utility.log(in.readLine()); 1Nz\3]-
sHeader=httpConnection.getHeaderFieldKey(i); kahv1s-
if(sHeader!=null) ?z6C8T~+
{ ]8^2(^3ct
if(sHeader.equals("Content-Length")) fkYQ3d,`
{ OV[-m;h|
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Zwcb5\Q
break; ovl@[>OB
} yP-Dj ,
} I}:/v$btM
else *n47.(a2i
break; 9.R_=
} `>*P(yIN
} M_e!s}F
catch(IOException e){e.printStackTrace ();} ck}y-,>,[O
catch(Exception e){e.printStackTrace ();} b9U2afd
ql4T@r3l}3
8177x7UG2[
Utility.log(nFileLength); ?1d_E meG2
T:-Uy&pBEN
R[Rs2eS_
return nFileLength; ,ToED
} Mk?9`?g.
suVS!} C
~UnfS};U
//保存下载信息（文件指针位置） RsbrD8*AD
private void write_nPos() vw3W:TL
{ 2|cIu 'U
try{ GP[$&8\M
output = new DataOutputStream(new FileOutputStream(tmpFile)); ZGrV? @o,6
output.writeInt(nStartPos.length); [`&cA#C9Yp
for(int i=0;i<nStartPos.length;i++) #<JrSl62(K
{ G{J9Fb8
// output.writeLong(nPos); %H@fVWe2wT
output.writeLong(fileSplitterFetch.nStartPos); }X$>84s>[P
output.writeLong(fileSplitterFetch.nEndPos); AkF1Hj
} %8ul}}d9
output.close(); $&4Zw6"=
} U!Lws#\X
catch(IOException e){e.printStackTrace ();} j04Q3d \f
catch(Exception e){e.printStackTrace ();} ed{9UJWh
} XH. _Z
HqbTJ!a
ED6H
//读取保存的下载信息（文件指针位置） i"b*U5k
private void read_nPos() Y8d%L;b[D
{ < ;g0?M\
try{ { sZrI5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); kN_LD-
int nCount = input.readInt(); r8xH A
nStartPos = new long[nCount]; !b7H
nEndPos = new long[nCount]; ^a(q7ZfY
for(int i=0;i<nStartPos.length;i++) Kq1sGk
{ OS!47Z /q
nStartPos = input.readLong(); )yK!EK\
nEndPos = input.readLong(); l"-D@]"
} C>;}CH|X
input.close(); iU3co|q7
} NO<myN+N
catch(IOException e){e.printStackTrace ();} J@$>d
catch(Exception e){e.printStackTrace ();} uIR_p\)
} X@cV']#V
)TWf/Lcp
c>^_4QQ
private void processErrorCode(int nErrorCode) c{E-4PYbah
{ t512]eqhb(
System.err.println("Error Code : " + nErrorCode); |[qI2-el?
} aw,8'N)
B1GSZUd^?0
$Fo ,$
//停止文件下载 iX,Qh2(ig
public void siteStop() vEb~QX0~
{ isaT0__8
bStop = true; $%jV%k
for(int i=0;i<nStartPos.length;i++) ~E)I+$,
fileSplitterFetch.splitterStop(); Mn=_lhWK
JRG7<s$
_[<I&^%
} }3+(A`9h f
} M--6oR7
//负责部分文件的抓取 3~ qgvAr
**FileSplitterFetch.java 'Hq}h)`
*/ gKPV*
package NetFox; xNx!2MrR;
*BF1Sso
2^juLXc|R
import java.io.*; 3U}z?gP[
import java.net.*; CfVz'
lUp 7#q
:gR`rc!
public class FileSplitterFetch extends Thread { #de]b
zRKg>GG`
OtC/)sX
String sURL; //File URL F|"NJ*o}
long nStartPos; //File Snippet Start Position m1frN#3
long nEndPos; //File Snippet End Position . E.OBn
int nThreadID; //Thread's ID k<St:X%.O
boolean bDownOver = false; //Downing is over 5$y<nMP
boolean bStop = false; //Stop identical !|}>Y
FileAccessI fileAccessI = null; //File Access interface `W-:@?PmQx
HezCRtxRcc
|~>8]3. Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Hj5b.fB
{ 5Po.&eS
this.sURL = sURL; wp@c;gK7
this.nStartPos = nStart; t!K|3>w
this.nEndPos = nEnd; tV<Au
nThreadID = id; t!PFosFp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Wy|=F~N
} rm2TWM|
KLoHjBq
BtjsN22
public void run() pE=wP/#
{ 8*|@A6ig
while(nStartPos < nEndPos && !bStop) fc M~4yP?
{ 3GaM>w}>W
7%0PsF _
N!P* B$d
try{ #$A6s~`B
URL url = new URL(sURL); wi&m(f(~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }g`A*y;t
httpConnection.setRequestProperty("User-Agent","NetFox"); JiRW|+`pe
String sProperty = "bytes="+nStartPos+"-"; {Xl 5F.q
httpConnection.setRequestProperty("RANGE",sProperty); lD{9o2
Utility.log(sProperty); )`L!eN
Z3I<
&3AGj,
InputStream input = httpConnection.getInputStream(); k6dSj>F>
//logResponseHead(httpConnection); 8I@_X~R
Lrz>00(*4
DTJ~.
byte[] b = new byte[1024]; wD*_S}]
int nRead; %T88K}?=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) VD1*br^,
{ KC
nStartPos += fileAccessI.write(b,0,nRead); ??k^Rw+0R
//if(nThreadID == 1) oW-luC+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "--rz;+K
} Ar>-xCTD
(0Y6tcV]R
~DCw [y
Utility.log("Thread " + nThreadID + " is over!"); hmks\eb~
bDownOver = true; \l#=p+x5
//nPos = fileAccessI.write (b,0,nRead); Fn6>n04v
} bZ0r/f,n$
catch(Exception e){e.printStackTrace ();} aLP2p]
} rJR"[TTJ
} ;zs4>>^>
>YLwWU<X
+]B^*99
//打印回应的头信息 uYJ6"j
public void logResponseHead(HttpURLConnection con) QHA<7Wg
{ _sw,Y!x%dF
for(int i=1;;i++) c~p4M64
{ ]2tX'=X
String header=con.getHeaderFieldKey(i); [<bfwTFsl
if(header!=null) 8_W<BXW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ib]{rmaP
Utility.log(header+" : "+con.getHeaderField(header)); qA&N6`
else ]W]Vkkg]
break; FJ~Dg3F1
} ij%\ld9kd
} U JY`P4(
`y m^0x8
:h?Zg(l
public void splitterStop() _G[5S-0 [
{ #j'OrD
bStop = true; (5VP*67
} O[Nc$dc
NaLec|6<t
~^:/t<N
} G^oBu^bq~
>H[&Wa+_
= R; 0Ed&b
/* 8!E$0^)c|
**FileAccess.java 8%2*RKj
*//文件访问(定位，写) /1t(e._
package NetFox; v?5Xx{ym
import java.io.*; qH$G_R#)8B
7w YSP&$
^uC1\!Q1
public class FileAccessI implements Serializable{ ZA+$ZU^
J?u",a]|H"
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <#LHL
RandomAccessFile oSavedFile; 5"k_Ms7R,
long nPos; sl>4O]N
;?bRRW
pn>zuHe
public FileAccessI() throws IOException pT:CvJ
{ &A]*"lt|w
this("",0); J3g>#N]='(
} }G_ i+
-N~*h
PUF"^9v
public FileAccessI(String sName,long nPos) throws IOException [Kx_%Le
{ KhYGiVA
oSavedFile = new RandomAccessFile(sName,"rw"); cBiv=!n
this.nPos = nPos; Ond"Eq=r
oSavedFile.seek(nPos); R2Lq,(@-
} 6D6=5!l
>J|I
{b8!YbG
public synchronized int write(byte[] b,int nStart,int nLen) _ i.CvYe
{ JaiYVx(
int n = -1; XLI'f$w&
try{ i%D/@$\D6
oSavedFile.write(b,nStart,nLen); vUY?Eb[
n = nLen; A<QYW,:|
} )k- 7mwkZ
catch(IOException e) i=]IUjx<
{ CSR6
e.printStackTrace (); /%=p-By<V
} `N;u#z
L*11hyyk
{>pB
return n; O=G2bdY{,
} ^7vhize
Yk6fr~b
's(0>i
} WOzdYeeG
m%'9zL c
HkGzyDt
/* g=:%j5?.e
**SiteInfoBean.java jrvhTej
*/ av&dGsFP
package NetFox; 9Or3X/:o
!s9<%bp3
`9kjYSd#E
public class SiteInfoBean { 7a->"W
fZ 17
e}-uU7O
private String sSiteURL; //Site's URL Wi'BX#xCB
private String sFilePath; //Saved File's Path W9ZT=#>)[
private String sFileName; //Saved File's Name qL,QsRwN
private int nSplitter; //Count of Splited Downloading File VABrw t
ig7)VKr
[`yiD>
public SiteInfoBean() b'St14_
{//nSplitter的缺省值为5 Z[slN5]([
//default value of nSplitter is 5 1Hy
this("","","",5); tt6ElP|D
} 2sk^A ly
Cx} Yp-
_Oh;._PS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _|g(BK2}
{ Xa Yx avq
sSiteURL= sURL; >OBuHqC
sFilePath = sPath; U3&*,xeU@H
sFileName = sName; I^qk`5w
this.nSplitter = nSpiltter; /1gKc}rB2
7=6p
VQ$=F8ivG
} mdoy1a
3Yp_k
OHR9u
public String getSSiteURL() V89!C?.[]1
{ 7Q/v#_e(
return sSiteURL; LGgEq-
} |&o1i~Y
BB1'B-O
K/, B
public void setSSiteURL(String value) J3}^\k=p"
{ +pnT6kU|
sSiteURL = value; nv2Y6e}dG
} mO?G[?*\
wGBQ.Ve[
'.#KkvE##
public String getSFilePath() ?MPM@9
{ }^pnwo9vV
return sFilePath; _(0!bUs>
} |U8;25Y
w-HgC
{MO`0n; rt
public void setSFilePath(String value) [f:>tRdH
{ qF%wl
sFilePath = value; &bRmr/D
} ^8 AV#a
'i%Azzv
13}=;4O
public String getSFileName() ~g;(`g
{ t/u$Ts
return sFileName; Bb}JyT
} @:oMlIw;
49 fs$wr@
6K[s),rdv
public void setSFileName(String value) Yc"G="XP;
{ __-rP
sFileName = value; R0gjx"U
} R =mawmQ2
^r(2 r
LZX-am`%
public int getNSplitter() o//N"S.)
{ kVe^g]F
return nSplitter; s><RL]+{G+
} +7sdQCO(Co
&j2L-)
V<\:iNXX{
public void setNSplitter(int nCount) b0rC\^x
{ A:cc @ku
nSplitter = nCount; z }R-J/xr2
} q^n6"&;*
} {>5z~OV
V.1sb pI
bO9F rEz5
/* %UV_ 3
**Utility.java 5u~Ik c~
*/ deda=%w0
package NetFox; Nr|.]=K)5n
<Zl0$~B:5
]\+bx=
public class Utility { Gvtd )9^<
C3G?dZKv2
8ftLYMX@
public Utility() rQ30)5^V|
{ :*/<eT_
TJ?}5h5
85w D<bN27
} |uj1T=ZY
yJ/m21f
//线程睡眠 Mff_j0D
public static void sleep(int nSecond) E@0wt^
{ E{wVf_K
try{ U11rj,7
Thread.sleep(nSecond); fR_)e:
} 0 m";=:(w
catch(Exception e) j<"0ym)A
{ FGy7KVR
e.printStackTrace (); AWh{dM
} m&Ms[X
} qWw@6VvoQ
"h2;65@
//日志 6Ck?O/^
public static void log(String sMsg) U87VaUr
{ *h@nAB\3
System.err.println(sMsg); <saS2.4
} )#xd]~<
dm8veKW'l
:*0k:h6g
public static void log(int sMsg) `vL R;D
{ #y-OkGS ^
System.err.println(sMsg); bsP:tFw>
} Y^2Ma878
} :M1+[FT
y{!`4CxF
UF,T
/* hy W4=
**TestMethod.java 4JU#3
*/ A>R ^iu
package NetFox; 43,- t_jV
K*7*`6iU
5\:#-IYJ
public class TestMethod { rouD"cy
nFw&vR/q
03$Ay_2
public TestMethod() G U0zlG] C
{ ///xx/weblogic60b2_win.exe 3|P P+<o
try{ v@Otp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _q3SR[k+`
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )Qw|)='-
SiteFileFetch fileFetch = new SiteFileFetch(bean); ln3x1^!
fileFetch.start(); (0Hhn2JA
} _L%/NXu,
catch(Exception e){e.printStackTrace ();} 0:v7X)St
P:ys--$"
*v8Cj(69
} Fe"0Hp+
|+suGqo
IW6;ZDP
public static void main(String[] args) *`|.:'
{ cMC1|3
new TestMethod(); @<>](4D
} lJ}G"RTm
} sBwkHsDD
点击下载更多相关资料