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)); {"@E_{\
} (7?jjH^4
for(int i=0;i<nEndPos.length-1;i++) I>%@[h,+
{ '/GZ,~q
nEndPos = nStartPos[i+1]; O`2hTY\
} +HfZs"x
nEndPos[nEndPos.length-1] = nFileLength; ehr,+GX
} ALl0(<u67
} 5}he)2*uD
;eiqzdP
)NCSO b
//启动子线程 [LrA_N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; L7 g4'
for(int i=0;i<nStartPos.length;i++) XZ1WY(
{ JB(P-Y#yyA
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), WG(%Pkowv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), u{(-`Al}L
nStartPos,nEndPos,i); G&v. cF#Y'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VQ'DNv| 9
fileSplitterFetch.start(); h$I 2T
} TI^M9;b
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jjU("b=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ZY{zFg9
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^laf!kIP
nEndPos = " + nFileLength); $ZfoJR]%
// fileSplitterFetch[nPos.length-1].start(); RMO6kbfP
c(!8L\69V}
EP}NT)z,{
//等待子线程结束 2` j#eB1
//int count = 0; s5D<c'-
//是否结束while循环 Q(7M_2e7
boolean breakWhile = false; )ZQML0}P;
[;8vO=Z
zx=AT
while(!bStop) M`gr*p
{ Yn1CU
write_nPos(); Fc.1)yh.
Utility.sleep(500); V.12
breakWhile = true; u<a =TPAU
4&/m>%r
EE[JXoke
for(int i=0;i<nStartPos.length;i++) [SA$d`B/
{ \<4Hp_2?
if(!fileSplitterFetch.bDownOver) J<=k [Q
{ iJem9XXb
breakWhile = false; oar`xH$C
break; =EdLffU[J
} XbL\l
} /8tF7Mmr
if(breakWhile) `Wy8g?d;bn
break; 6<+8[o
kr6^6I.
H_+F~P5RC
//count++; 84UI)nE:Q
//if(count>4) ?~s23%E
// siteStop(); _M9-n
} 7l|D!`BS
Lyj0$wbH`
3f^~mTY9>]
System.err.println("文件下载结束！"); _$YT*o@0J
} [t}$W*hY
catch(Exception e){e.printStackTrace ();} [Csv/
} %9P)Okq
CxW-lU3G`
cnwpd%]o
//获得文件长度 3^J~ts{*
public long getFileSize() X'KkIo :
{ 9;k!dM
int nFileLength = -1; ! fSM6Vo
try{ Bq)aA)gF
URL url = new URL(siteInfoBean.getSSiteURL()); d:1TSJff%/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OJ Y_u[
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Ed
X__>r ?oJ
6pi^rpo
int responseCode=httpConnection.getResponseCode(); x0dO^D
if(responseCode>=400) v9K{oB
{ ~[d|:]
processErrorCode(responseCode); m_n*_tX
return -2; //-2 represent access is error 6fr@y=s2:
} 'AjDB:Mt$
Bm&%N?9
\"^.>+
String sHeader; .ECT
?Pw(
!;ipLC;e}
for(int i=1;;i++) "8|a4Y+F
{ aO]FQ#l2b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =f*Wj\
//Utility.log(in.readLine()); rS/}!|uAu
sHeader=httpConnection.getHeaderFieldKey(i); >:yU bo)
if(sHeader!=null) hJcN*2\:
{ x&PVsXdt5m
if(sHeader.equals("Content-Length")) g<"k\qs7
{ e$+/;MRq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qqR8E&Y{
break; l{b*YUsz>
} :4, OA
} DHnu F@M
else QY]G+3W
break; 3vK,vu q
} @p}"B9h*^
} (iw)C)t*u
catch(IOException e){e.printStackTrace ();} n'-?CMH`
catch(Exception e){e.printStackTrace ();} =TzmhX5
uh_2yw_
X_nxC6[m%
Utility.log(nFileLength); Y']D_\y
= rLL5<
16N+
return nFileLength; WMw]W&
} MU/3**zoW
_RcFV
!^EdB}@yS
//保存下载信息（文件指针位置） ]@D#<[5\
private void write_nPos() %Z#s9QC
{ 39+6ZTqx
try{ g.re`m|Aj
output = new DataOutputStream(new FileOutputStream(tmpFile)); I/ q>c2Pw$
output.writeInt(nStartPos.length); ^&mJDRe
for(int i=0;i<nStartPos.length;i++) %Qc5_of
{ #^FDFl
// output.writeLong(nPos); B}YpIb]d
output.writeLong(fileSplitterFetch.nStartPos); ozr82
output.writeLong(fileSplitterFetch.nEndPos); |`50Tf\J
} @&G< Np`
output.close(); ZC\&n4~7
} k-uwK-B}v+
catch(IOException e){e.printStackTrace ();} rIg5Wcd
catch(Exception e){e.printStackTrace ();} o :tz_5
} Xob,jo}a
}#h>*+Q
Q5:8$ C}+
//读取保存的下载信息（文件指针位置） />,Tq!i\4}
private void read_nPos() SpB\kC"K
{ =Hs[peO*
try{ s/"?P/R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6HyndB^
int nCount = input.readInt(); ">pt,QV
nStartPos = new long[nCount]; wC~ra:/?:7
nEndPos = new long[nCount]; 4tb y N
for(int i=0;i<nStartPos.length;i++) _poe{@h!
{ ^XIVWf#`H
nStartPos = input.readLong(); ;=?f0z<
nEndPos = input.readLong(); dmkd.aP4
} Zoi\r
input.close(); l1h;ng6
} s^n}m#T
catch(IOException e){e.printStackTrace ();} k]<E1 c/
catch(Exception e){e.printStackTrace ();} uuA q\YZy/
} :172I1|7
2W_p)8t>b
DG!H8^
private void processErrorCode(int nErrorCode) S|pMX87R
{ \~:Uj~
System.err.println("Error Code : " + nErrorCode); Vif0z*\e{
} ;GgW&*|
0Ek+ }`
/s\_"p
//停止文件下载 2unaK<1s
public void siteStop() MzY~-74aF
{ dD Zds k+!
bStop = true; P})Iwk|Z
for(int i=0;i<nStartPos.length;i++) 7K|: 7e(
fileSplitterFetch.splitterStop(); F{g^4
{4@+ 2)l
LXm5f;
} d\R]>
} w!=Fi
//负责部分文件的抓取 p? dXs^ c
**FileSplitterFetch.java I,:R~^qJ8v
*/ G q" [5r"
package NetFox; EPZ^I)
P9\!JH!
.Kn)sD1
import java.io.*; `a!:-.:v
import java.net.*; !p4y@U{
]ZB^Hi_
6^oQ8unmS
public class FileSplitterFetch extends Thread { ZDI%?.U
soH M5<U
0(Hhb#WDh\
String sURL; //File URL eoC@b/F4
long nStartPos; //File Snippet Start Position `Z}7G@ol
long nEndPos; //File Snippet End Position pnvHh0ck_
int nThreadID; //Thread's ID )<kId4E
boolean bDownOver = false; //Downing is over kbxy^4"X
boolean bStop = false; //Stop identical @LzqQ[
FileAccessI fileAccessI = null; //File Access interface Zy>iaG9}
i09w(k?
Gg\805L@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException wQ4IQ!
{ #s!q(Rc
this.sURL = sURL; q Z,7q
this.nStartPos = nStart; \1AtBc&
this.nEndPos = nEnd; epWO}@ b a
nThreadID = id; /lC&'hT
fileAccessI = new FileAccessI(sName,nStartPos);//定位 sUfYEVjr
} }[[
vu&%e\gM
_ 2WG6y;
public void run() z g@,s"`>
{ Ls<.&3X2
while(nStartPos < nEndPos && !bStop) nY#V~^|
{ wO&edZ]zb^
wClX3l>y
M%3\]&
try{ hr+,-j
URL url = new URL(sURL); x}`]9XQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oPX `/X#
httpConnection.setRequestProperty("User-Agent","NetFox"); ^st.bzg+[
String sProperty = "bytes="+nStartPos+"-"; 0u?{"xH{+}
httpConnection.setRequestProperty("RANGE",sProperty); 2f%G`4/p
Utility.log(sProperty); 6%p$C oR
)]=1W
FAS+*GFz
InputStream input = httpConnection.getInputStream(); <h$Nh0
//logResponseHead(httpConnection); 1;\A./FVv
tj:Q]]\M
b)SU8z!NV&
byte[] b = new byte[1024]; N34.Bt
int nRead; rc*iL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1|?8g2Vf
{ Koi
nStartPos += fileAccessI.write(b,0,nRead); aXoD{zA
//if(nThreadID == 1) 6O`s&T,t
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D['z/r6F
} W-QBC- 3
Y1?"Ut
/-#1ys#F=
Utility.log("Thread " + nThreadID + " is over!"); =aWj+ggd@
bDownOver = true; GJUorj&
//nPos = fileAccessI.write (b,0,nRead); ,s%1#cbR
} e~#"#?
catch(Exception e){e.printStackTrace ();} Nn"[GB
} ,~R`@5+
} BVKr 2v
pzo9?/-
>y2;sJ4]D%
//打印回应的头信息 SNV[KdvP*
public void logResponseHead(HttpURLConnection con) uB(16|W>S
{ x2#5"/~4
for(int i=1;;i++) arCi$:-z@
{ !J5k?J&{=
String header=con.getHeaderFieldKey(i); X#qmwcF
if(header!=null) J3]W2m2Zw
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ECO4ut.d
Utility.log(header+" : "+con.getHeaderField(header)); F/"Q0%(m
else "Ih>>|r
break; V)$y
} 3f u*{8.XZ
} ^J?ExMu
'f#i@$|]
+<G |Ru-
public void splitterStop() p19[qy~.
{ F-\Swbx+
bStop = true; 3'd(=hJ45$
} ){AtV&{$
pJ` M5pF
A9*( O)
} [j6EzMN
4Y):d!'b
W"m\|x
/* A@8Ot-t:\2
**FileAccess.java di@4'$5#
*//文件访问(定位，写) \m3'4#
package NetFox; rjmKe*_1V
import java.io.*; y:U'3G-
WIytgM
4%8}vCs
public class FileAccessI implements Serializable{ LvWl*:z
,0'Yj?U>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >m}U|#;W
RandomAccessFile oSavedFile; K[wOK
long nPos; |x2+O
1'skCR|!<
^i"C%8
public FileAccessI() throws IOException 9,?\hBEu
{ vybQ}dscn
this("",0); KGMX >t'
} `y&d
? m$uqi
|-WoR u
public FileAccessI(String sName,long nPos) throws IOException dDuT,zP
{ h8b*=oq
oSavedFile = new RandomAccessFile(sName,"rw"); s6#@S4^=\
this.nPos = nPos; ZS&n,<a5L}
oSavedFile.seek(nPos); -=W"
} dXkgWLI~
"4VC:"$f
'bH',X8gF
public synchronized int write(byte[] b,int nStart,int nLen) 0p8Z l
{ uCA!L)$
int n = -1; @/S6P-4
try{ IrAc&Ehul
oSavedFile.write(b,nStart,nLen); '}3m('u
n = nLen; T6X%.tR>`
} 45Z"U<I,9
catch(IOException e) 8+m[ %5lu
{ XA cpLj]
e.printStackTrace (); ep"YGx[V
} 64Ot`=A"
lpW|GFG
h)%}O.ueB
return n; Wvhg:vup
} }uI(D&?+h
A),nkw0X
so* lV
} GZL{~7n
J`6X6YZ
~~U2Sr
/* ?e? mg
**SiteInfoBean.java Hx}K wS
*/ -qki^!Y?
package NetFox; |E\0Rv{H3
aZ$$a+
3pxm0|
public class SiteInfoBean { sZ,MNF8i
_n.2'
LPjsR=xi
private String sSiteURL; //Site's URL DVu_KT[Hd
private String sFilePath; //Saved File's Path +O<0q"E
private String sFileName; //Saved File's Name !B=Oc!e=K
private int nSplitter; //Count of Splited Downloading File ;WQ@dC
"J0,SFu:
9m2_zfO[w
public SiteInfoBean() 8\-Q(9q(
{//nSplitter的缺省值为5 IAr
//default value of nSplitter is 5 HaP0;9q
this("","","",5); {HV$hU+_)Q
} SZOcFmC?
P!?Je/Tz]
8S&Kf>D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) q!iMc
{ L lP
sSiteURL= sURL; Qm|Q0u
sFilePath = sPath; '4PAH2&n
sFileName = sName; nwwKef(
this.nSplitter = nSpiltter; #+V5$
[OI&_WIw
zw{cli&S
} #1MEmt
,2F4S5F~rC
s*R\!L
public String getSSiteURL() j@0/\:1(U
{ X-oHQu5
return sSiteURL; !Jo3>!,j
} #4(/#K 1j
q&IO9/[dk
20hF2V
public void setSSiteURL(String value) sSLs%)e|:
{ Mis t,H7
sSiteURL = value; 2#4_/5(j*
} )oOcV%
@MfuV4*
zcrLd={
public String getSFilePath() -e=p*7']
{ LGN,8v<W(
return sFilePath; ,}M@Am0~
} ETP}mo
({3hX"C@Q
VjU;[
public void setSFilePath(String value) =RR225
{ )!1; =
sFilePath = value; G"CV S@
} Sd;/yC8
0G/VbS
Jtj_Rl !
public String getSFileName() W_EM k
{ $!c)%qDq
return sFileName; C24[brf
} gY AXUM,
8?S32Gdu
Q]_3 #_'
public void setSFileName(String value) zr9o
{ V/Hjd`n)`i
sFileName = value; |]a=He;
} @Taj++ua
)u7*YlU\I
Wxl^f?I`:
public int getNSplitter() QDlEby m
{ n{F$,a
return nSplitter; ~mc7O
} yD iL
q<>
cq'opjLf5
public void setNSplitter(int nCount) q!#e2Dx
{ vjG: 1|*e
nSplitter = nCount; Sf>R7.lpP
} ?PNG@OK
} =z'w-ARy
MnvFmYgxA
ZF :e6em
/* "|CzQ&e
**Utility.java ^(I4Do~}
*/ mrDIt4$D
package NetFox; 66<3zadJZU
SCk2D!u
l-"c-2-!
public class Utility { "J]_B
nAn/Vu
o+W5xHe^1
public Utility() ]trVlmZXH}
{ ReOp,A/y
f[3DKA
`r+"2.z*
} 27*u^N*z@
jw$3cwddH
//线程睡眠 4C^;lK
public static void sleep(int nSecond) P"0S94o:5J
{ V,bfD3S3
try{ THirh6
Thread.sleep(nSecond); b:.aZ7+4
} &eV& +j
catch(Exception e) W)jO 4,eO
{ SU OuayE
e.printStackTrace (); 9I8{2]
} >N>WOLbb7(
} 9l2,:EQ*
&^e%gU8!\
//日志 #%k!`?^fbK
public static void log(String sMsg) *6~ODiB
{ F)/}Q[o8
System.err.println(sMsg); JqTkNKi/s
} &P&LjHFK
V6"<lK8"
#|fa/kb~
public static void log(int sMsg) vCT5do"C&
{ fk)ts,p?
System.err.println(sMsg); tS,nO:+x
} |du@iA]dP
} *,hS-
t4pc2b
Dt)\q^bH)
/* N+x0"~T}I
**TestMethod.java 3DnlXH(h1
*/ 9^h\vR|]S
package NetFox; mD-qJ6AM
<`*}$Zh
Pk[:+. f(
public class TestMethod { vJDK]p<}
obRR))
U>6MT@\
public TestMethod() p+U}oC
{ ///xx/weblogic60b2_win.exe Tx?,]c,(u
try{ 1a3rA
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T6JN@:8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f>ohu^bd
SiteFileFetch fileFetch = new SiteFileFetch(bean); Zws[}G"7h
fileFetch.start(); LAeJz_9U
} g1VdP[Y#
catch(Exception e){e.printStackTrace ();} emOd<C1A
x/Se /C
[Hz_x(t26
} 0ZPwEP
9tsI1]1[m
Mit,X
public static void main(String[] args) V%'`nJ!
{ XVAyuuTg\
new TestMethod(); 4>nY't;0
} PHl{pE*
} G$pTTT6#
点击下载更多相关资料