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)); NO%|c|B|
} )I^)*(}
for(int i=0;i<nEndPos.length-1;i++) zV9 =
{ w?*'vF_2:#
nEndPos = nStartPos[i+1]; 4"rb&$E
} $v2S;UB v*
nEndPos[nEndPos.length-1] = nFileLength; %!1@aL]pQ
} \Or]5ogT'
} 6uv'r;U]
})Ix.!p
eU<]h>2
//启动子线程 w/)e2CH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;w>Q{z
for(int i=0;i<nStartPos.length;i++) !^rITiy
{ gt(X!iN]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ss*LgK_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m(Pz7U.Q
nStartPos,nEndPos,i); 3g4vpKg6c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *=r@vQ
fileSplitterFetch.start(); O p!
} <<~lV5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^*j[&:d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); y?rK5Yos
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", T(t <Ay?c
nEndPos = " + nFileLength); 0$Qn#K
// fileSplitterFetch[nPos.length-1].start(); xV }:M
Wl@0TUK
lUy*549,
//等待子线程结束 IX > j8z[
//int count = 0; w0F:%:/
//是否结束while循环 m7bn%j-{$f
boolean breakWhile = false; n:{-Vvt
6ba2^3GH
23.y3t_?
while(!bStop) MV:<w3!
{ Z)b)v
write_nPos(); !IQfeoT
Utility.sleep(500); l#<}|b
breakWhile = true; F5om-tzy
4@ydK
4OB~h]Vc
for(int i=0;i<nStartPos.length;i++) kM}ic(K
{ Z:r$;`K/
if(!fileSplitterFetch.bDownOver) TWD|1 di0
{ /;]B1T7
breakWhile = false; bRY4yT
break; ^+Y-=2u:
} EusfgU:
} ),W(TL
if(breakWhile) xOX*=Wv
break; (PE8H~d
D{3 x}5
Z n"TG/:
//count++; 2*3B~"
//if(count>4) >V ]*mS%K
// siteStop(); 8kn]_6:3i
} HCn]#
NC[GtAPD3
SFXfo1dqH
System.err.println("文件下载结束！"); A(_^_p.|
} av|6r#
catch(Exception e){e.printStackTrace ();} 1'@lg*^9
} o 0cc+
(,)vak&t
!EyGJa[i
//获得文件长度 8M(|{~~3:
public long getFileSize() is_dPc
{ $ M[}(m
int nFileLength = -1; A(!ZZ9Wc
try{ u" NIG
URL url = new URL(siteInfoBean.getSSiteURL()); )b:~kuHi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +X|m>9
httpConnection.setRequestProperty("User-Agent","NetFox"); Wvzzjcr(j
N4JqW
]R3pBC"Jv
int responseCode=httpConnection.getResponseCode(); v1tN DyM6
if(responseCode>=400) 9^[5!SMzCj
{ 0;m$a=
processErrorCode(responseCode); dp%pbn6w
return -2; //-2 represent access is error G\aLg
} Z2pN<S{5
\w@_(4")Qb
Rs(CrB/M
String sHeader; | 9\7xT
ZE3ysLkm
yADN_
for(int i=1;;i++) (w@MlMk
{ #B.w7y5*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Osvz 3UMY3
//Utility.log(in.readLine()); "3>*i!i
sHeader=httpConnection.getHeaderFieldKey(i); ?H86Wbz
if(sHeader!=null) )su <Ji*
{ IP4b[|ef
if(sHeader.equals("Content-Length")) H2pXJ/XF
{ &s}@7htE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %(7wZ0Z
break; <:yq~?
} tX`[6`
} ff5 Lwf{{
else nluyEK
break; 4\eX=~C>:
} :pF]TY"K.
} O]r3?=
catch(IOException e){e.printStackTrace ();} {-7yZ]OO$
catch(Exception e){e.printStackTrace ();} EX_sJc
; K 6Fe)
Z!=Pc$?
Utility.log(nFileLength); A%czhF
yU8Y{o;:
QmkC~kK1.
return nFileLength; 8UY=}R2C
} 6+f>XL#w
36A.h,~
E{]|jPdr
//保存下载信息（文件指针位置） "VVR#H}{
private void write_nPos() ,IZxlf%
{ $CYpO}u#
try{ r(2'0JQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); :R*^Izs=
output.writeInt(nStartPos.length); V1fvQ=9
for(int i=0;i<nStartPos.length;i++) ?e|:6a+[f
{ ~1]2A[`s!
// output.writeLong(nPos); LU IT=+
output.writeLong(fileSplitterFetch.nStartPos); 5\kZgXWIh
output.writeLong(fileSplitterFetch.nEndPos); Y" +1,?yH
} 1S.e5{
output.close(); 2Q'XB
} 0gb]Kjx
catch(IOException e){e.printStackTrace ();} P)j9\ muc
catch(Exception e){e.printStackTrace ();} eYX_V6c
} ~m09yc d<
Jc#)T;#6
V-U ^O45
//读取保存的下载信息（文件指针位置） gwB>oi*OE
private void read_nPos() a:%5.!Vd
{ hv8[_p`>
try{ 7te!>gUW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~Z/`W`
int nCount = input.readInt(); WUK.>eM0
nStartPos = new long[nCount]; =O:ek#Bp
nEndPos = new long[nCount]; 4Z p5o`*g2
for(int i=0;i<nStartPos.length;i++) 3%4Mq6Q`
{ D.CsnfJ
nStartPos = input.readLong(); y<x_v )k-
nEndPos = input.readLong(); JO6vzoS3
} <7-,`
input.close(); h/bYtE
} ?UhAjtYIS
catch(IOException e){e.printStackTrace ();} |iJZC
catch(Exception e){e.printStackTrace ();} }/}`onRZ
} -/7=\kao%
h+u|MdOY\
=v`&iL~m
private void processErrorCode(int nErrorCode) y^|3]G3
{ j%y+W{Q[
System.err.println("Error Code : " + nErrorCode); hA1hE?c`
} vc{]c }
w,#W&>+&
l'lDzB+.*
//停止文件下载 &EJ,k'7$
public void siteStop() W9m[>-Ew
{ .lj!~_
bStop = true; =ZIFS
for(int i=0;i<nStartPos.length;i++) eV=sDx
fileSplitterFetch.splitterStop(); b0=AQ/:
jL).B&
T:~W.3
} i-vJ&}}
} tsC|R~wW
//负责部分文件的抓取 [_G0kiI}W"
**FileSplitterFetch.java 2DqHqq9m
*/ im[gbac
package NetFox; G6F['g);
C^:&3,
[>9"RzEl
import java.io.*; iKH T
import java.net.*; Uk ;.Hrt.
oc%le2
XlJux_LD:
public class FileSplitterFetch extends Thread { >@e%,z
;9 n8on\
r_Yl/WW
String sURL; //File URL `a-T95IFy
long nStartPos; //File Snippet Start Position 'n.9qxY;
long nEndPos; //File Snippet End Position z:jF)N
int nThreadID; //Thread's ID WY~[tBi\
boolean bDownOver = false; //Downing is over 8/$iCW
boolean bStop = false; //Stop identical P2RL\`<"
FileAccessI fileAccessI = null; //File Access interface &_9eg
I2!HXMrp
4n)Mx*{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \iSBLU
{ #l% \}OC
this.sURL = sURL; ouZ9oy(}a
this.nStartPos = nStart; v86`\K*0Y
this.nEndPos = nEnd; x&b-Na3Xi
nThreadID = id; c0p=/*s(
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SFNd,(kB*z
} Z'm%3
%--5bwZi
9TS=>
public void run() -^Va]Lk
{ 4DM|OL`w
while(nStartPos < nEndPos && !bStop) ]-LE'Px|
{ 5)i0g
?S:_J!vX{
Q</HFpE
try{ mU>*NP(L
URL url = new URL(sURL); kakWXGeR
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3H%WB|
httpConnection.setRequestProperty("User-Agent","NetFox"); IH:Cm5MV
String sProperty = "bytes="+nStartPos+"-"; %b4(wn?n:B
httpConnection.setRequestProperty("RANGE",sProperty); I;Y`rGj
Utility.log(sProperty); EPnB%'l\c
t^;Fq{>
SntYi0,`
InputStream input = httpConnection.getInputStream(); *heQ@ww
//logResponseHead(httpConnection); O~]G(TMs8W
&}=,8Gt1G
Ap9wH[H
byte[] b = new byte[1024]; =B%e0M
int nRead; F4gc_>{|
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }}R!Y)
{ {0{$.L
nStartPos += fileAccessI.write(b,0,nRead); o-Arfc3Q
//if(nThreadID == 1) ;H|M)z#[Z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5LH ]B
} q8]k]:r
#TF
7Wn]l!
Utility.log("Thread " + nThreadID + " is over!"); r5wXuA,Um
bDownOver = true; %z(=GcWm
//nPos = fileAccessI.write (b,0,nRead); J/2pS
} "!?Ya{
catch(Exception e){e.printStackTrace ();} d_B5@9e#
} W)O'(D
} niBpbsO
L]")TQ
4`]1W,t
//打印回应的头信息 1_]l|`Po
public void logResponseHead(HttpURLConnection con) AOUO',v
{ "ET"dMxU
for(int i=1;;i++) X[6z
{ aa]v7d
String header=con.getHeaderFieldKey(i); &|*|
if(header!=null) .C?gnOq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nJC}wh2d#
Utility.log(header+" : "+con.getHeaderField(header)); b7mP~]V
else -&tiM v
break; m!(K
} +R$KEGu~0Y
} Mq$=zsj
x|5/#H
YgDasKFm'
public void splitterStop() z"`?<A&u
{ yRDLg c
bStop = true; VvKH]>*
} 1tc9STYR}
|JQ05nb
cKAl 0_[f"
} na)ceN2h
x #g,l2_!
Q5JeL6t
/* +^:K#S9U
**FileAccess.java :{2$X|f 3
*//文件访问(定位，写) x]T;W&s
package NetFox; *^ BE1-
import java.io.*; yD"sYT
Mk;j"ZDF
v>R.ou(
public class FileAccessI implements Serializable{ =c'LG
A:Z:&(NtE:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K.~U%v}
RandomAccessFile oSavedFile; 5N/;'ySAE_
long nPos; m\=u/Zip
In2D32"F
XMdYted
public FileAccessI() throws IOException 2rM i~8T
{ &D#v0!e~x
this("",0); Z(P#]jI]
} wd*Jq
3-D!ZS&
HS7!O
public FileAccessI(String sName,long nPos) throws IOException Lif mYn[
{ .Pi67Kj,
oSavedFile = new RandomAccessFile(sName,"rw"); bMYRQ,K`C
this.nPos = nPos; gUcE,L
oSavedFile.seek(nPos); +nuQC{^>
} j&9~OXYv
Df9}YI;?
&knnWm"
public synchronized int write(byte[] b,int nStart,int nLen) jQhf)B
{ iy 5
int n = -1; I~I%z'"RQd
try{ 1N&U{#4
oSavedFile.write(b,nStart,nLen); 7>'F=}6[Y
n = nLen; =@'"\ "Nh
} uH#NJoRO
catch(IOException e) jn[a23;G)
{ <|4j<U
e.printStackTrace (); ?g&]*zc^\
} c8u0\X,
/D q]=P
DuWP)#kg
return n; _:z~P<%s
} yQ}~ aA#h
d dPJx<
I6\3wU~).
} A28w/=e7
#[8gH>7
I'gnw~
/* i0P+,U
**SiteInfoBean.java ^V:YNUqp#
*/ Z#Fw 1
package NetFox; }MX`WW0\]Z
k}/: xN"
[Xrq+O,
public class SiteInfoBean { ;KhYh S(q
(7IF5g\
TcC=_je460
private String sSiteURL; //Site's URL sk5\"jna
private String sFilePath; //Saved File's Path ,%C$~+xjM
private String sFileName; //Saved File's Name 4Vs;Y&t]
private int nSplitter; //Count of Splited Downloading File G`n-WP
L=$P
m} V,+E
public SiteInfoBean() 2#R"#Q!
{//nSplitter的缺省值为5 bhI8b/
//default value of nSplitter is 5 [ /D/
this("","","",5); #G,e]{gs
} S.I<Hs
B5cTzY.h-
oH;Y}h
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?1d_E meG2
{ u,C-U!A
sSiteURL= sURL; ("aYjKk
sFilePath = sPath; k91Y"_&
sFileName = sName; e'ZgF~
this.nSplitter = nSpiltter; 8_uDxd
czp5MU_^
ZpdM[\Q-
} R'F|z{8
emHi=[!i
E )PEKWK\
public String getSSiteURL() >3ODqRu
{ [:o#d`^
return sSiteURL; bUBuJ
} C/E3NL8
."lY>(HJ
8'YL!moG|
public void setSSiteURL(String value) B!<I[fvK
{ { sZrI5
sSiteURL = value; koUH>J:
} ^a(q7ZfY
b/ynCf8X
&O'yhAP] j
public String getSFilePath() iZ58;`
{ .1}u0IbJ
return sFilePath; HiWZ?G
} Ft]sTA+C
X@cV']#V
[-%oO
public void setSFilePath(String value) [Nq4<NK
{ )&w\9}B:
sFilePath = value; S`-z$ph}
} Wbc %G8
Fb_~{q
6q5V*sJ&
public String getSFileName() 2Zl65
{ ubgq8@;
return sFileName; MXhS\vF#m
} %~eZrG.
E{FNsa
~v5tx
public void setSFileName(String value) G1D(-X4ALZ
{ @P8q=j}l9
sFileName = value; _x:K%1_[
} \'p)kDf
jHFdDw|N`
20J:_+=]
public int getNSplitter() uW[<?sFG
{ 5ogbse"
return nSplitter; t%/5$<!b
} !?KY;3L:
9eV@v
gs. K,xma
public void setNSplitter(int nCount) Wima=xYe\5
{ l\S..B +
nSplitter = nCount; iA:CPBv_mu
} BKGwi2]Ry
} h[ tOY
'SuYNA)
{yJ{DU?%Y
/* M#:Mwa$
**Utility.java ;z&p(e
*/ 9zX\ioT
package NetFox; #-@dc
- @
jdhhvoQ
public class Utility { Yc9 M6=E^
=n;ileGm+^
<yIJ$nBx
public Utility() 4YdmG.CU
{ (+9@j(
)[/+j"F
%T88K}?=
} yvVs9"|0
u[cbRn,W
//线程睡眠 zRu}lJ1#W$
public static void sleep(int nSecond) AN^;~m^
{ Q~`]0R159e
try{ cnI!}Bu
Thread.sleep(nSecond); >bmL;)mc&
} SA}]ZK P
catch(Exception e) y\ouIsI77
{ ;Ni+TS
e.printStackTrace (); u dH7Q&"
} d]+g3oy `
} G`w7dn;&
n|{x\@VeF
//日志 4F/Q0"
public static void log(String sMsg) &L+u]&!6C
{ R$v{ p[
System.err.println(sMsg); y|c]r!A
} +
HSyohP87
hYF<Wn3L
public static void log(int sMsg) y%iN9 -t
{ ?e yo2:-$
System.err.println(sMsg); e PlEd'Z
} @|r*yi
} ~,dj)x 3M
\9<aCJxN
ck-wMd
/* eBG7]u,Q
**TestMethod.java Wrt3p-N"D
*/ evZ{~v&/
package NetFox; ~^:/t<N
N#Y4nllJ
=|=9\3po
public class TestMethod { \O`B@!da~
X,^J3Ek>O
G+=&\+{#4
public TestMethod() '^n2]<
{ ///xx/weblogic60b2_win.exe &QLCij5:
try{ 7G!SlC X}W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,Rz,[KI|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OP%h`
SiteFileFetch fileFetch = new SiteFileFetch(bean); A'p"FYlCW
fileFetch.start(); 1z0&+C3z
} {WT"\Xj>B?
catch(Exception e){e.printStackTrace ();} 7[^:[OEE
8Q?)L4.]
@C7#xGD
} -Z)$].~|t
1KAA(W;nq
hekAics6S
public static void main(String[] args) v`bX#\It
{ pu,/GBG_
new TestMethod(); _ i.CvYe
} _hK7hvM>
} X Oc0j9Oa
点击下载更多相关资料