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)); &w{: qBa
} =q<t,UP8
for(int i=0;i<nEndPos.length-1;i++) ^ Q
{ ^-g-]?q
nEndPos = nStartPos[i+1]; LDYk\[81
} j%Wip j;c
nEndPos[nEndPos.length-1] = nFileLength; I9hZ&ed16
} dw3H9(-lp
} `s~[q
u$ a7
';KZ.D
//启动子线程 P$Fq62;}r4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; DlxL:
for(int i=0;i<nStartPos.length;i++) <>R\lPI2
{ 66l+cb
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &b=OT%D~FU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NflRNu:-
nStartPos,nEndPos,i); 9PWqoz2c
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2SJ|$VsLaE
fileSplitterFetch.start(); `FRdo
} arb'.:[z^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L%31>)8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6rh^?B
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", H57wzG{xG
nEndPos = " + nFileLength); VY j pl
// fileSplitterFetch[nPos.length-1].start(); Ct9dV7SH
18AlQ+')?w
?h3t"9
//等待子线程结束 9e0t
//int count = 0; 9N;y^ Y\
//是否结束while循环 0<u(!iL
boolean breakWhile = false; 4rH:`494
F+285JK
m?`?T
while(!bStop) =m/BH^|&W
{ [f#7~
write_nPos(); w~Jy,[@n
Utility.sleep(500); k@9CDwh*s
breakWhile = true; ?^!: Lw
WNo<0|X
p(pL"
for(int i=0;i<nStartPos.length;i++) ^9 Pae)
{ OHK]=DH:M
if(!fileSplitterFetch.bDownOver) Ry"N_Fb
{ 905Lk>rB
breakWhile = false; 7Lx=VX#]q
break; lzK,VZ=mM
} #KwK``XC4
} e8VtKVcY
if(breakWhile) gbjql+Mx+
break; |s, Add:S
j[Oh>yG
/<)kI(gf
//count++; aJSBG|IC
//if(count>4) 9 M!U@>
// siteStop(); K%3{a=1
} 'I5~<"E
baz~luM
v|GDPq
System.err.println("文件下载结束！"); 2_CJV
} y9X1X{
catch(Exception e){e.printStackTrace ();} ?vV&tqnx%
} ^8{:RiN6e~
|\J! x|xy
xv~EwT)
//获得文件长度 z1m$8-4
public long getFileSize() -"/l)1ox,
{ #Y<(7
int nFileLength = -1; TRku(w1f
try{ N\W4LO6
URL url = new URL(siteInfoBean.getSSiteURL()); DH'0#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <a)L5<#
httpConnection.setRequestProperty("User-Agent","NetFox"); q*d@5
zi= gOm
$-"V 2
int responseCode=httpConnection.getResponseCode(); 'h{| ]
if(responseCode>=400) :{M1]0NH
{ "Is0:au+?}
processErrorCode(responseCode); 2PG= T/
return -2; //-2 represent access is error ]_y0wLq
} xOBzT&
TY]-L1$
xL}~R7
String sHeader; A&7~]BR\
#ByrX\
sX|bp)Nw
for(int i=1;;i++) 8mv}-;
{ qN(,8P\90
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]n^TN r7
//Utility.log(in.readLine()); (cdtUE8
sHeader=httpConnection.getHeaderFieldKey(i); taqmtXU=(
if(sHeader!=null) Jpr`E&%I6
{ /6nj 4.xxc
if(sHeader.equals("Content-Length")) t{o&$s93
{ Ob m%\h
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y(Q!OeC
break; Vc?=cQ'c
} al{}p
} B|.8+Q
else =`KV),\
break; G_)(?
} iw0|A
} ~#nbD-*#
catch(IOException e){e.printStackTrace ();} ]97`=,OUg
catch(Exception e){e.printStackTrace ();} 'X/(M<c
7MhN>a;A\
XS`=8FQ
Utility.log(nFileLength); $p~X"f?0
uH=^ILN.
;SVAar4r
return nFileLength; MH h;>tw
} rLJjK$_x
'o% .Qx
b,o@m
//保存下载信息（文件指针位置） JmJNq$2#c
private void write_nPos() xI,7ld~
{ ^K`Vqo
try{ KdU&q+C^
output = new DataOutputStream(new FileOutputStream(tmpFile)); @zAav>
output.writeInt(nStartPos.length); dXewS_7
for(int i=0;i<nStartPos.length;i++) .|x"'3#
{ xe9V'wICp(
// output.writeLong(nPos); x'hUw*
output.writeLong(fileSplitterFetch.nStartPos); PBY^m+
output.writeLong(fileSplitterFetch.nEndPos); mYw9lM
} .jvRUD8A7
output.close(); m5\/7 VC
} :+$/B N:iO
catch(IOException e){e.printStackTrace ();} :9f/d;Mo3
catch(Exception e){e.printStackTrace ();} ?*: mR|=
} D<UX^hU
-A)XYz
" UxKG+
//读取保存的下载信息（文件指针位置） I%gDqfdL
private void read_nPos() BY!M(X jrZ
{ M?m)<vMr*
try{ X9/]<Y<!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); c/ s$*"
int nCount = input.readInt(); ^yp`<=
nStartPos = new long[nCount]; ,BuEX#ZaBl
nEndPos = new long[nCount]; $5S/~8g(
for(int i=0;i<nStartPos.length;i++) oH]"F
{ yjB.-o('
nStartPos = input.readLong(); DqbU$jt`
nEndPos = input.readLong(); f<}>*xH/k
} CZ.XEMN\
input.close(); YpwMfl4
} m* JbZT
catch(IOException e){e.printStackTrace ();} _tO:,%dL
catch(Exception e){e.printStackTrace ();} (Aw!K`0Y1
} Q~S3d
{Bm7'%i
&&er7_Q
private void processErrorCode(int nErrorCode) 6O# xV:Uc<
{ iqh"sx{5bp
System.err.println("Error Code : " + nErrorCode); z*BGaSX %
} pG0Ca](
AW<z7BD
t)h{ w"v
//停止文件下载 )EptyH
public void siteStop() cO^}A(Ma(
{ 2pn8PQfg)
bStop = true; vivU4:uH3
for(int i=0;i<nStartPos.length;i++) ;"j>k>tg
fileSplitterFetch.splitterStop(); _7qGo7bpN
DP<[Uz&
A57e]2_
} Z%1{B*(e
} >p,FAz>
//负责部分文件的抓取 W\l"_^d*
**FileSplitterFetch.java _|qs-USA
*/ WEVV2BJ
package NetFox; /C"?Y'
5U5)$K'OA
,a1 1&"xl
import java.io.*; -&3mOn& (1
import java.net.*; =abBD
zy!mP
*^_ywqp
public class FileSplitterFetch extends Thread { P@pJ^5Jf
,[t>N>10TH
!w #x@6yq
String sURL; //File URL Rd^X.
long nStartPos; //File Snippet Start Position -|aNHZr
long nEndPos; //File Snippet End Position sUEvL(%nY
int nThreadID; //Thread's ID 6y d/3k
boolean bDownOver = false; //Downing is over 0b~{l;
boolean bStop = false; //Stop identical 0CFON2I
FileAccessI fileAccessI = null; //File Access interface syR +;
Lkl+f~m
q]r?s%x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException byB ESyV!O
{ ZuIw4u(9
this.sURL = sURL; R;2q=%
this.nStartPos = nStart; /ig'p53jL
this.nEndPos = nEnd; 1j":j%9M
nThreadID = id; +kN/-UsB
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QYj8c]8f
} w +~,Mv\
x8q3 Njr
|r%lJmBB
public void run() xHo iu$i6
{ C.rLog#
while(nStartPos < nEndPos && !bStop) VvJ]*D+e
{ u^NZsuak
dOfEEqPI
&Y/Myh[P
try{ Fo86WP}
URL url = new URL(sURL); nL]-]n;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <~}#Q,9
httpConnection.setRequestProperty("User-Agent","NetFox"); nm.~~h+8M
String sProperty = "bytes="+nStartPos+"-"; h..D1(M
httpConnection.setRequestProperty("RANGE",sProperty); @%}4R`S0
Utility.log(sProperty); 1deNrmp%
4EtP|
K)!Nf.r$9
InputStream input = httpConnection.getInputStream(); %e,X7W`'2
//logResponseHead(httpConnection); VM[U&g<8n
Dd:;8Xo
SC6cFyp2
byte[] b = new byte[1024]; FsdxLMwk1
int nRead; *'&mcEpg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Rz_fNlA
{ JDA:)[;
nStartPos += fileAccessI.write(b,0,nRead); JE$aYs<(TF
//if(nThreadID == 1) 8p)*;Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \vR&-+8dk
} +o94w^'^$b
!f^'-
AO"pm
Utility.log("Thread " + nThreadID + " is over!"); gPrIu+|F
bDownOver = true; gBZ1Weu-'
//nPos = fileAccessI.write (b,0,nRead); |&hu3-(
} },@1i<Bb
catch(Exception e){e.printStackTrace ();} 5C^oqUZ
} d l<7jM?
} 6IyD7PQ
[EX@I =?
/v^1/i
//打印回应的头信息 Aa#WhF
public void logResponseHead(HttpURLConnection con) ;Fi(zl
{ !gm;g}]szG
for(int i=1;;i++) >PD*)Uq&
{ yS)73s/MrY
String header=con.getHeaderFieldKey(i); V7\@g
if(header!=null) qbwX*E~;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 1aQR9zg%
Utility.log(header+" : "+con.getHeaderField(header)); ![OKmy
else 7Y>17=|
break; GVaIZh<
} S3oSc<&2
} vg6'^5S7
jZX2)#a!
hCcAAF*I;5
public void splitterStop() #ARQB2V
{ |*w}bT(PfR
bStop = true; `?H yDny
} :"pA0oB
,iQRf@#W_b
uN)o|7
} e{<r<]/j
+v7mw<6s
fA k]]PU
/* #_b U/rk)*
**FileAccess.java ?^< E#2a
*//文件访问(定位，写) c[I4'x
package NetFox; FYs-vW{
import java.io.*; !((J-:=
+mgmC_Q(0
BcfW94
public class FileAccessI implements Serializable{ wM"PJG
/4}B}"`Sl=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mT7B#^H
RandomAccessFile oSavedFile; kX2bU$1Q,i
long nPos; i#lnSJ08
dV( "g],
ky^p\dMh
public FileAccessI() throws IOException =@%Ukrd@
{ #Oeb3U
this("",0); k[`9RGT
} a->;K+
@Weim7r
4w\@D>@}H
public FileAccessI(String sName,long nPos) throws IOException /ehmy(zL
{ ^J TrytIB
oSavedFile = new RandomAccessFile(sName,"rw"); [K\Vc9
this.nPos = nPos; B3j
oSavedFile.seek(nPos); j<HBzqP%6
} oVK3=m@{
S{qc1qj
1j9R^
public synchronized int write(byte[] b,int nStart,int nLen) - DO
{ Ob+Rnfx37
int n = -1; M$9?{8m
try{ m~#f L
oSavedFile.write(b,nStart,nLen); (2oP=9m
n = nLen; -Dx_:k|k
} \x,q(npHi
catch(IOException e) {c;][>l
{ r?w^#V
e.printStackTrace (); N'8u}WO
} Y M<8>d
vH^6O:V
'K L"i
return n; nI63Ns
} (&W&1KT
C[Ap&S
]r^/:M
} g p2S
2+2Gl7" s
bI_6';hq!
/* 3u)NkS=
**SiteInfoBean.java X#|B*t34
*/ 7<T1#~w4L
package NetFox; Q=,6W:j
$y0[AB|V
k"kGQk4
public class SiteInfoBean { %|tDb
_{]\} =@
i; qb\
private String sSiteURL; //Site's URL .d JX,^
private String sFilePath; //Saved File's Path GV+K] KDI
private String sFileName; //Saved File's Name -|"[S"e
private int nSplitter; //Count of Splited Downloading File TQ/EH~Sz
JZa^GW:YQh
rkF>c
public SiteInfoBean() y*BS %xTF
{//nSplitter的缺省值为5 z^ai *
//default value of nSplitter is 5 b6mSPH@
this("","","",5); >o]!-46
} R 2{kS
95wi~^^
ji|+E`Nii
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _6tir'z
{ o4%H/|Oq.
sSiteURL= sURL; Ap:mc:
sFilePath = sPath; wb#ZRmx}
sFileName = sName; e2~$=f-
this.nSplitter = nSpiltter; bvxol\7;
@d+NeS
,EE,W0/zzM
} YR 5C`o
P1r)n{;
vky@L!&,
public String getSSiteURL() D<16m<b
{ ,esryFRG
return sSiteURL; 7CK3t/3D
} B$Z%_j&
z154lY}K
u{6b>c|,X
public void setSSiteURL(String value) t-;zgW5mwF
{ iFJ1}0<(x
sSiteURL = value; R/_bk7o]H
} zF)&o}
69 >-
/S9(rI<'
public String getSFilePath() `/"rs@
{ 17 k9h?s*
return sFilePath; ccdP}|9e
} pZ@)9c
|g$n-t
/.1yxb#Z?,
public void setSFilePath(String value) ]g3RVA%\l
{ )wt mc4'
sFilePath = value; R7nT,7k.
} 1?oX"
Az`c? W%
K1gZ>FEY|N
public String getSFileName() M2$.Yom[
{ __3s3YG
return sFileName; NrVE[Z#
} )'+ tb\g
G2 E4
9W7 ljUg
public void setSFileName(String value) Wq+a5[3"
{ wm'a)B?
sFileName = value; m\0Xh*
} tbH`VD"u
zc`gm~@
-J06H&/k
public int getNSplitter() X0}+X'3
{ 6dNW2_
return nSplitter; 6H#4iMeh
} C'wRF90
Sb/`a~q^
xa=Lu?t%<
public void setNSplitter(int nCount) +=V[7^K;
{ vGX}zzto
nSplitter = nCount; $$5E+UDOs
} Ik\n/EE
} +D@+j
S.I3m-
n&n WY+GEo
/* j6JK4{
**Utility.java '#oNOU
*/ Rs +),
package NetFox; F%]ZyO9
<TDp8t9bU
-5 Q gJ
public class Utility { B&M-em=
[Zpx :r}
l9P=1TL
public Utility() 4#D<#!]^
{ ,(@JNtx
M SnRx*-
g0Ff$-#7
} :kU-ol$
#H5i$ o
//线程睡眠 Fmd^9K
public static void sleep(int nSecond) !1b4q/
{ 5fT"`FL?
try{ auai@)v6
Thread.sleep(nSecond); ;usR=i36b
} `q$a p$?
catch(Exception e) YaT6vSz
{ %*A|hK+G:W
e.printStackTrace (); JG:li} N
} 0^-1/Ec
} okkMx"
HPus/#j'+
//日志 ] oMtqkiR
public static void log(String sMsg) XH`W(
{ zgnZ72%
System.err.println(sMsg); z|k0${iu#
} Wp |qv
J6C/`)+w
LFskNF0X
public static void log(int sMsg) $SbgdbX
{ nkxv,_)ZT
System.err.println(sMsg); "8#EA<lsS
} JnY.]:
} KB$SB25m
6]^~yby P
QB"Tlw(
/* n90DS/Yx
**TestMethod.java xe&w.aBI>
*/ t9\}!{<s
package NetFox; tYk!Y/O}
2N}UB=J
t8?$q})RL
public class TestMethod { JGRL&MG4
unB`n'L
579<[[6~d2
public TestMethod() '~\\:37+
{ ///xx/weblogic60b2_win.exe &*YFK/]
try{ 2e<u/M21>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,vh$G 7D
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N87)rhXSo,
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q{:=z6&
fileFetch.start(); U(rY,4'
} UID0|+%Y
catch(Exception e){e.printStackTrace ();} lvd`_+P$
Rh :|ij>B
"2=v:\~=
} #7r13$>!
]5',`~jkF
8fSY@
public static void main(String[] args) X? l5}
{ /_D_W,#P
new TestMethod(); 3Ow bU
} t8ZzBD!dP
} f6])M)
点击下载更多相关资料