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)); UNv!G/i-5
} dOaCdnd~
for(int i=0;i<nEndPos.length-1;i++) :?ZrD,D
{ ndN*X'
nEndPos = nStartPos[i+1]; x2HISxg
} bV'r9&[_6
nEndPos[nEndPos.length-1] = nFileLength; >e.KD)qA
} tV pXA'"!x
} t3^`:T\
D(<0tU^[
>P}XCAU
//启动子线程 g;[t1~oF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8vR'<_>Q
for(int i=0;i<nStartPos.length;i++) +mR^I$9
{ - 3PLP$P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7cB{Iq0+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), SfY9PNck\
nStartPos,nEndPos,i); G8?Do+[
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VhMVoW
fileSplitterFetch.start(); z_KCG2=5
} `]4(Z"R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G^VOA4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #bG6+"g{=L
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ve.P{;;Ky
nEndPos = " + nFileLength); o>yXEg
// fileSplitterFetch[nPos.length-1].start(); ZpBP#Y*
ij3W8i9'
S+t2k&pm
//等待子线程结束 )~nieQEZQ
//int count = 0; eFA,xzp
//是否结束while循环 DC BN89#
boolean breakWhile = false; )^6Os2
`*kl>}$
AkO);4A;Jd
while(!bStop) Y8lZ]IB
{ s0x/2z
write_nPos(); 6 A#xFPYY{
Utility.sleep(500); RDy&i
breakWhile = true; lt2MB#
x`IWo:j
MujEjD "|
for(int i=0;i<nStartPos.length;i++) ]Z85%q^`
{ _T8S4s8q
if(!fileSplitterFetch.bDownOver) @8A[HP
{ bt.3#aj
breakWhile = false; sD{Wc%5
break; BYa#<jXtAT
} 4Xt`L"f
} u.?jWvcv
if(breakWhile) WT1y7+_g(d
break; 7#9%,6Yi
"f~OC<GdYs
f:~$x
//count++; 5e7\tBab
//if(count>4) !su773vo
// siteStop(); ?q2Yk/P
} -F3~X R
G^dzE/:
%4YSuZg
System.err.println("文件下载结束！"); tw\1&*:
} m^TN6/])
catch(Exception e){e.printStackTrace ();} pm:-E(3#
} SK 5]7C2
y>gw@+
~kDJ-V
//获得文件长度 '^[+]
public long getFileSize() V*Xr}FE
{ )ZrB-(u~k
int nFileLength = -1; fM*?i"j;Y
try{ m@w469&<(q
URL url = new URL(siteInfoBean.getSSiteURL()); oK4xRv8Hd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ZBN,%P!P0
httpConnection.setRequestProperty("User-Agent","NetFox"); r=AA /n<
5dD8s-;^T
k9:|CEP
int responseCode=httpConnection.getResponseCode(); [/ertB
if(responseCode>=400) pQC|_T#u
{ zfg+gd)Z
processErrorCode(responseCode); AP1ZIc6
return -2; //-2 represent access is error _p'@.P
} y c 8h}`
D.x8=|;
KU+\fwYpnk
String sHeader; Y"yrc0'&T
EVw{G<
R osU~OK
for(int i=1;;i++) `Lavjmfr2V
{ {d0-.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hdSP#Y'-
//Utility.log(in.readLine()); gG}H5uN
sHeader=httpConnection.getHeaderFieldKey(i); (~E-=+R[$&
if(sHeader!=null) g#7Q-n3^
{ _9p79S<+
if(sHeader.equals("Content-Length")) |>m'szca4
{ <o*b6m%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1\Pjz Lj
break; !y'>sAf
} *vEj\
} ,Oy$q~.
else B'`25u_e<
break; >7~*j4g
} $ Y^0l
} l"DHG`kb
catch(IOException e){e.printStackTrace ();} l(}L-:@A
catch(Exception e){e.printStackTrace ();} V3r)u\ o'
~w|h;*Bj
I.T?A9Z
Utility.log(nFileLength); ">eled)O
g0}jE%)
uozq^sy
return nFileLength; j6XHH&ZEb
} (6:.u.b
HuU$x;~
o^*:
//保存下载信息（文件指针位置） P3Lsfi.
private void write_nPos() >P\eHR,{-
{ Gau@RX:O
try{ jX(${j<
output = new DataOutputStream(new FileOutputStream(tmpFile)); x|dP-E41\
output.writeInt(nStartPos.length); F'|e:h
for(int i=0;i<nStartPos.length;i++) q1x[hv3 pP
{ WG,1%=M@
// output.writeLong(nPos); r=vY-p
output.writeLong(fileSplitterFetch.nStartPos); wQjYH!u,YZ
output.writeLong(fileSplitterFetch.nEndPos); ^RT_Lky
} K@g ~
output.close(); dg|x(p#
} J@E]Fl
catch(IOException e){e.printStackTrace ();} bn8maYUZ
catch(Exception e){e.printStackTrace ();} ytjZ7J['{
} t!6uz
yI#qkl-
jl(D;JnF
//读取保存的下载信息（文件指针位置） Tj_K5uccU}
private void read_nPos() UXdc'i g
{ Qj_)^3`e
try{ x>TIx[x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }5(_gYr
int nCount = input.readInt(); Cb? !+U
nStartPos = new long[nCount]; h9<PP2.(
nEndPos = new long[nCount]; 1hgIR^;[b
for(int i=0;i<nStartPos.length;i++) ,pdzi9@=t
{ &y=OZ !M
nStartPos = input.readLong(); `Ds=a`^b
nEndPos = input.readLong(); mI4GBp
} hZL!%sL7
input.close(); vo\'ycPv
} R.HvqO
catch(IOException e){e.printStackTrace ();} qCfEv4
catch(Exception e){e.printStackTrace ();} ht]n*
} Q[K$f%>
1+N'cB!y
i7r)9^y
private void processErrorCode(int nErrorCode) @-\=`#C**
{ xZ;eV76
System.err.println("Error Code : " + nErrorCode); Tgtym"=xd
} ~K3Lbd| r
/}>8|#U3y
wzd(=*N
//停止文件下载 D})/2O p
public void siteStop() #-G@p
{ Ot`%5<E^
bStop = true; fx(8 o+
for(int i=0;i<nStartPos.length;i++) #<9'{i3
fileSplitterFetch.splitterStop(); % R25, V
d$bO.t5CLh
P![ZO6`:W'
} ,e;,+w=~E
} @S}j=k
//负责部分文件的抓取 vnQFq
**FileSplitterFetch.java f~a 7E;y
*/ e.DN,rhqI
package NetFox; #I0FWZ>W
3?"gfw W
iBbaHU*V
import java.io.*; :'C?uk ?
import java.net.*; -p)`ob-
nKr'cb
.u#Hg'oP
public class FileSplitterFetch extends Thread { ; I-6H5
(UjaL@G
yGt[Qvx#
String sURL; //File URL Ew PJ|Z^
long nStartPos; //File Snippet Start Position <_|@~^u
long nEndPos; //File Snippet End Position ?zutU w/m
int nThreadID; //Thread's ID *v K~t|z
boolean bDownOver = false; //Downing is over a BMV6'
boolean bStop = false; //Stop identical S$fS|N3]%
FileAccessI fileAccessI = null; //File Access interface jFe8s@7
vvxD}p=y
Lv/}&'\(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u;rmqo1
{ RS}_cm0
this.sURL = sURL; l{C]0^6>i
this.nStartPos = nStart; XfVdYmii
this.nEndPos = nEnd; UMd.=HC L
nThreadID = id; hN=kU9@knC
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NdLe|L?c
} k`N*_/(|n
">1wPq&
M*3G
public void run() %pOz%v~
{ SWI\;:k
while(nStartPos < nEndPos && !bStop) dazML|1ow
{ 6*S/frE
NR_3nt^h
GiuE\J9i
try{ (EWGX |QA
URL url = new URL(sURL); |&MoQxw@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TK' 5NM+4
httpConnection.setRequestProperty("User-Agent","NetFox"); (VN'1a (
String sProperty = "bytes="+nStartPos+"-"; oz{X"jfu
httpConnection.setRequestProperty("RANGE",sProperty); Ar/P%$Zfq
Utility.log(sProperty); LsIZeL^
!BkE-9v?w
Ce<z[?u
InputStream input = httpConnection.getInputStream(); oowofi(E
//logResponseHead(httpConnection); {%>~ ]9E
gE@Pb
dS 4/spNq
byte[] b = new byte[1024]; FN!?o:|(
int nRead; *lLCH,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) URm<Ji
{ ?_AX;z
nStartPos += fileAccessI.write(b,0,nRead); 8i73iTg(
//if(nThreadID == 1) fmv:vs /9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]$s)6)kW
} V*te8HIe
zsQkI@)sO
r-EIoZ"P
Utility.log("Thread " + nThreadID + " is over!"); Y)]VlV!`
bDownOver = true; C/N;4
//nPos = fileAccessI.write (b,0,nRead); [O_5`X9|
} wAi7jCY%OY
catch(Exception e){e.printStackTrace ();} ATc!c +
} uQ[,^Ee&/
} 420K6[
vD9.X}l]
'J&R=MD
//打印回应的头信息 jA:'P~`Hj
public void logResponseHead(HttpURLConnection con) P(8Yz W
{ (NR( )2
for(int i=1;;i++) `&fW<5-
{ =d5;F`m
String header=con.getHeaderFieldKey(i); GR*sk#{
if(header!=null) Hc\@{17
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =2GKv7q$x,
Utility.log(header+" : "+con.getHeaderField(header)); @(6i 1Iwu9
else a6z0p%sIZ
break; {e2ZW]
} ET9tn1
} yc7b%T*Y
BWYv.&=(
jMI30
public void splitterStop() p{GO-gE@
{ *(r9c(xa
bStop = true; ERK{smL
} UJL'4 t/
5D7 L)>
x@oxIXN
} 7#UJ444b~
r 56~s5A
kkHK~(>G
/* [vb#W!M&|
**FileAccess.java AtHkz|sl
*//文件访问(定位，写) R|qNyNXo[
package NetFox; z@19gD#8
import java.io.*; 4|\M`T
u|$HA>F[
I'{Ctc
public class FileAccessI implements Serializable{ J7{D6@yLS
o+}1M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 X~o;jJC
RandomAccessFile oSavedFile; `:r-&QdU o
long nPos; .e3@fq
q$v0sTk0Y
snkMxc6c[
public FileAccessI() throws IOException s@%>
{ SbL7e#!!
this("",0); TK'y-5W
} IpzU=+h
m$_l{|4z
*tpS6{4=#7
public FileAccessI(String sName,long nPos) throws IOException A9ld9R
{ Txe*$T,(
oSavedFile = new RandomAccessFile(sName,"rw"); "X?Zw$gRud
this.nPos = nPos; v?3xWXX,
oSavedFile.seek(nPos); o\Fv~^
} #;8VBbc\^
>HwVP.~HN
d<=!*#q;o
public synchronized int write(byte[] b,int nStart,int nLen) /03Wst
{ P>~Usuf4
int n = -1; qPDRB.K|}
try{ U_aI!`WXd
oSavedFile.write(b,nStart,nLen); ^e]O >CJ
n = nLen; ~qL/P 5*+
} ~n0Exw(
catch(IOException e) C{l-l`:
{ NhYUSk ~u
e.printStackTrace (); X[w]aJnAr
} "BpDlTYM
"#8^":,4
?AxB0d9z
return n; 9'|k@i:
} _M;{}!Gc&A
ca0vN^Ji
^a3 (QKS
} W95q1f#7
5\JV}
y[cc<wm$
/* "k"+qR`fH
**SiteInfoBean.java /s(PFN8#Y
*/ n2c(x\DA&
package NetFox; Ha ZV7
T51oNO%^
I-J%yutB
public class SiteInfoBean { EXW?)_pg
Ty!V)i
J- l[dC
private String sSiteURL; //Site's URL 2.{<C.BK{
private String sFilePath; //Saved File's Path "<&o;x<
private String sFileName; //Saved File's Name #sv}%oV,F
private int nSplitter; //Count of Splited Downloading File ib]<;t
rfgsas{F
i6;rh-M?.
public SiteInfoBean() /K+;HAUTn
{//nSplitter的缺省值为5 XCn;<$3w
//default value of nSplitter is 5 7:$dl#
this("","","",5); 4RQ38%> >j
} 3|3ad'
B<@a&QBTg
MScUrW!TA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qM^y@B2MO
{ 0f+]I=1\
sSiteURL= sURL; xTcY&
sFilePath = sPath; #^-'q`)
sFileName = sName; '}>8+vU`
this.nSplitter = nSpiltter; O7&OCo|b%>
vj#m#1\f
\ sz](X
} kY4h-oZ
!+UXu]kA
[>j.x2=
public String getSSiteURL() QqeF
{ _\,4h2(
return sSiteURL; t[b(erO'
} FY+@fy
5rA>2<\pQ
W^H[rX}=
public void setSSiteURL(String value) $'a]lR
{ pFo,@M
sSiteURL = value; 8L@@UUjr
} AMK3I`=8WO
&Fmen;(
"(+aWvb
public String getSFilePath() *Hh*!ePp
{ ;:)u rI?
return sFilePath; d _=44( -
} T?-K}PUcQ
L#_QrR6Sny
TjctK [db@
public void setSFilePath(String value) U[@B63];0
{ 4)N~*+~\h
sFilePath = value; MY&?*pV)
} z`8>$9
rV I-Yb
wS:`c J
public String getSFileName() F@X8a/;F-
{ "9H#pj -
return sFileName; ^DR`!.ttr
} x C>>K6Nb
+$GP(Uu,
n]wZ7z
public void setSFileName(String value) OgyHX>}bH
{ c5HW.3"
sFileName = value; -EU~ %/=m+
} e(-Vp7vXG
`&A-m8X
2FTJxSC
public int getNSplitter() IAbH_+7O
{ Uw>g^[V;
return nSplitter; `q1K%id
} 9t0NO-a
9KZLlEk5O
r6`KZ TU
public void setNSplitter(int nCount) 8~h.i1L
{ .n| M5X
nSplitter = nCount; WAh{*$Rpl
} 2ISnWzq;
} 0-A@X>6bs
?|we.{
N7qSbiRf<
/* <UO'&?G
**Utility.java >c8EgSZJ
*/ KZTT2KsYl
package NetFox; p%y|w
;(9q, )
QW}N,j$
public class Utility { C+c;UzbD
.^* .-8q
9.$k^|~
public Utility() k:kx=K5=4
{ Ja#ti y
. [\S=K|/
@Vac!A??:
} '>5W`lZ
Q68q76
//线程睡眠 ?i7}d@636
public static void sleep(int nSecond) *4F6U
{ &8uq5uKg
try{ '\.fG\xD
Thread.sleep(nSecond); ,XNz.+Ov
} ey>V^Fj
catch(Exception e) 0')O4IHH
{ }*I:0"WH
e.printStackTrace (); F&x9.
} =h9&`iwiu
} ril4*$e7^\
@'{m-?*
//日志 V8.o}BWY
public static void log(String sMsg) wqLY \
{ "]C$"JR
System.err.println(sMsg); 48 `k"Uy
} eE/E#W8
}<hyW9
(},TZ+u
public static void log(int sMsg) X!%CYmIRb
{ 4:p+C-gs
System.err.println(sMsg); Y^-faL7*\
} Cj x(Z]
} NiQ_0Y}
Wq1%
]ozZW:
/* IirXF?&t
**TestMethod.java yH0BNz8V
*/ 3-5X^!C
package NetFox; -_RMiGM?T
Oy^)lF/
,f;YJHEx8
public class TestMethod { $($26g
pIy+3&\e;
!!4` #Z0+#
public TestMethod() D> |R.{
{ ///xx/weblogic60b2_win.exe ' s6SKjZS
try{ AF}6O(C~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tz&oe
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ir%?J&C+t
SiteFileFetch fileFetch = new SiteFileFetch(bean); tGcp48R-:+
fileFetch.start(); w{1DwCLKq
} &v\
catch(Exception e){e.printStackTrace ();} ,dM}B-
{ ke}W
mPy=,xYyC
} }x^q?;7xW
~al4`:rRx1
Rh:edQ#
public static void main(String[] args) <V-D
{ GDgq 4vfj
new TestMethod(); V~> x\
} WML%yO\.;
} kCWaji_x%
点击下载更多相关资料