http断点续传简单实现（java)

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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)); (Y)2[j
} OWewV@VXR
for(int i=0;i<nEndPos.length-1;i++) lk 1\|Q I
{ 53:~a
nEndPos = nStartPos[i+1]; <8b1OdA
} (U&
nEndPos[nEndPos.length-1] = nFileLength; -SM_JR3<
} $$m0mK
} P5?VrZy
_ARG "
BFW b0;+
//启动子线程 Qa_V
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g:fvg!_v
for(int i=0;i<nStartPos.length;i++) R#hy2kA
{ PN93.G(W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), vQ*[tp#qU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0fewMS*
nStartPos,nEndPos,i); FJZ'P;3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |;US)B8}*Z
fileSplitterFetch.start(); Dq<la+VlO
} \~*<[.8~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), <{cY2cx~3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6 ^3RfF^W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", QZ&(e2z
nEndPos = " + nFileLength); [cnuK
// fileSplitterFetch[nPos.length-1].start(); o>8~rtl
<Ja&z M
1+Gq<]@G
//等待子线程结束 T]wI)
//int count = 0; kaCN^yQ
//是否结束while循环 Ge`7`D>L
boolean breakWhile = false; wL8ji>"
$L= Dky7
`*vO8v
while(!bStop) .JLJ(WM
{ *gwaW!=
write_nPos(); "/6#Z>y
Utility.sleep(500); 1k6asz^T
breakWhile = true; OY{fxBb
{C5:as
eP]y\S*P
for(int i=0;i<nStartPos.length;i++) #1haq[Uv7
{ /iO"4%v
if(!fileSplitterFetch.bDownOver) DKt98;
{ C<J*C0vQO
breakWhile = false; 8S#$'2sT
break; yDqwz[v b
} iKaX8c,zI
} /#Pm'i>B
if(breakWhile) u"qu!EY2
break; {*O%A
0FcDO5ia
-]0:FKW
//count++; CBd%}il
//if(count>4) bBs{PI2(p1
// siteStop(); O6Py
} 5&s6(?,Eu
9Do75S{(
p"hO6b%V
System.err.println("文件下载结束！"); 0;TiNrzg
} x4v:67_^
catch(Exception e){e.printStackTrace ();} &)k=ccm
} 73X*|g[O
^}~Q(ji7
hOB<6Tm[
//获得文件长度 n'mrLZw
public long getFileSize() SEI0G_wk$
{ fsjLD|?|:
int nFileLength = -1; i[KXkjr
try{ 9wR D=a
URL url = new URL(siteInfoBean.getSSiteURL()); z|3v~,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @]n8*n
httpConnection.setRequestProperty("User-Agent","NetFox"); q.=Q
H7+z"^s*
"~ID.G|<
int responseCode=httpConnection.getResponseCode(); SOR\oZ7
if(responseCode>=400) nqH[ y0
{ VvW4!1Dl
processErrorCode(responseCode); \YzKEYx+
return -2; //-2 represent access is error qR cSB
} HjK8y@j
.fzyA5@l
7Y@]o=DIc
String sHeader; Nmx\qJUR(
` 1+*-g^r
1K3XNHF
for(int i=1;;i++) /)TeG]Xg
{ -E\G3/*51
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /rZk^/'
//Utility.log(in.readLine()); /4Wf\ Zu
sHeader=httpConnection.getHeaderFieldKey(i); $EY[CA E
if(sHeader!=null) Xi"9y @
{ 0 8L;u7u
if(sHeader.equals("Content-Length")) tkV[^OeU>
{ qWW\d', .
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K{_~W yRF
break; H'3 pHb
} S=P}Jpq?Y;
} _:\rB
else Q(<A Yu
break; PFpFqJ)Cs"
} dsw^$R}
} nq?+b >//
catch(IOException e){e.printStackTrace ();} RTVU3fw
catch(Exception e){e.printStackTrace ();} <y?+xZM]#|
**m8 HD
2j4202
Utility.log(nFileLength); TFb7P/g
9)+!*(D
4e>f}u5
return nFileLength; ?&0CEfa?
} FMCA~N
XwEMF5[
D>jtz2y=D
//保存下载信息（文件指针位置） Ch?yk^cY
private void write_nPos() BD]J/o
{ KLM6#6`
try{ z#RwgSPw6
output = new DataOutputStream(new FileOutputStream(tmpFile)); H9jlp.F
output.writeInt(nStartPos.length); {G=>WAXo
for(int i=0;i<nStartPos.length;i++) e;=R8i
{ ^kK")+K
// output.writeLong(nPos); pWzYC@_W
output.writeLong(fileSplitterFetch.nStartPos); a`yCPnB(
output.writeLong(fileSplitterFetch.nEndPos); -ioO8D&!
} 0*]0#2Z
output.close(); prO&"t >
} )Mq4p'*A[
catch(IOException e){e.printStackTrace ();} VB/75xK_
catch(Exception e){e.printStackTrace ();} =UO7!vr;[
} ]z7pa^
0o7o;eN
-U>)B
//读取保存的下载信息（文件指针位置） ,hNs{-*
private void read_nPos() RoHX0
{ sifjmNP
try{ G:+D1J]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A\mSS
int nCount = input.readInt(); XU"G
nStartPos = new long[nCount]; Wx/PD=Sf&
nEndPos = new long[nCount]; *9KT@"v
for(int i=0;i<nStartPos.length;i++) H '5zl^8I
{ -"yma_
nStartPos = input.readLong(); $n8&5<
nEndPos = input.readLong(); Dp*:oMATx0
} @QJPcF"
input.close(); T^8`ji
} 68~]_r.a
catch(IOException e){e.printStackTrace ();} 1| WDbk
catch(Exception e){e.printStackTrace ();} D {E,XOi
} Xl$r720ZJr
E\4ZUGy0
~]%re9jGW
private void processErrorCode(int nErrorCode) rr1,Ijh{D
{ F'<XB~&o
System.err.println("Error Code : " + nErrorCode); :[?7,/w
} D@w&[IF
p&(z'd
mtFC H
//停止文件下载 meB9:w[m
public void siteStop() %j2:W\g:
{ }cW8B"_"
bStop = true; sn[<Lq
for(int i=0;i<nStartPos.length;i++) QWm g#2'
fileSplitterFetch.splitterStop(); Or/YEt}
aAu%QRq
(8S+-k?
} iU{\a,
} >PWDo
//负责部分文件的抓取 V:D?i#%,z
**FileSplitterFetch.java ,!AYeVq
*/ KdlUa^}D
package NetFox; V+'zuX
!Y^B{bh
_B4N2t$
import java.io.*; L eUp!
import java.net.*; gvjy'Rm
>0N$R|B&
(F R
public class FileSplitterFetch extends Thread { K#v@bu:'
v>hc\H1P
NCkrf]*F-
String sURL; //File URL l0!`>Xx[b
long nStartPos; //File Snippet Start Position !9C]Fs*`?
long nEndPos; //File Snippet End Position v~^*L iP+
int nThreadID; //Thread's ID *~#`LO
boolean bDownOver = false; //Downing is over {R~L7uR@O
boolean bStop = false; //Stop identical 3gCP?%R
FileAccessI fileAccessI = null; //File Access interface Kv5 !cll5
#B$_ily)
Fvv/#V^R
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =6'D/| 3
{ $xcU*?=K
this.sURL = sURL; ac43d`wpK
this.nStartPos = nStart; dm83YCdL
this.nEndPos = nEnd; @`sZV8
nThreadID = id; z[+pN:47
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *q1sM#;5
} KH$o X\v
>va9*pdJ
OYfP!,+bn
public void run() _rUsb4r
{ "y .(E7 6
while(nStartPos < nEndPos && !bStop) "X1{*
{ /h!iLun7I
a^L'-(
#Nv0d|0\
try{ @:u2{>Yl
URL url = new URL(sURL); 5)K?:7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !\Q/~p'jS
httpConnection.setRequestProperty("User-Agent","NetFox"); Y,%G5X@S<
String sProperty = "bytes="+nStartPos+"-"; #0M,g
httpConnection.setRequestProperty("RANGE",sProperty); ra\2BS)X
Utility.log(sProperty); &2Cu"O'.i
JR/^Go$^
yc$8X sns
InputStream input = httpConnection.getInputStream(); ps]s Tw
//logResponseHead(httpConnection); 8+~|!)a
0c:jwtf
""F'Nzy
byte[] b = new byte[1024]; _i&awm/U
int nRead; e,0Gc-X[B
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dzc.s8T(0
{ 5zII4ukn*
nStartPos += fileAccessI.write(b,0,nRead); b"#|0d0
//if(nThreadID == 1) )x&}{k6 %
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e0u*\b
} N|WR^MQD
Y]1b39O
RiAY>:
Utility.log("Thread " + nThreadID + " is over!"); sJ/?R:
bDownOver = true; ~%:23mIk
//nPos = fileAccessI.write (b,0,nRead); DadlCEZv
} ZTSNM)f
catch(Exception e){e.printStackTrace ();} WAbt8{$D
} >/F,Z%!&q
} (/l9@0Y.t
=C2,?6!
TL_8c][.4$
//打印回应的头信息 ijWn,bj
public void logResponseHead(HttpURLConnection con) ,U/ZG|=v
{ j'JNQo;q
for(int i=1;;i++) DW~< 8
{ ;GxKPy
String header=con.getHeaderFieldKey(i); {p(.ckze+
if(header!=null) liq9P,(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'Sjcm@ILm
Utility.log(header+" : "+con.getHeaderField(header)); ~I)\d/7o
else Vg4N7i
break; 6~0.YZ9
} /\M3O
} 0/JusQ
:Keek-E`e=
!pLQRnI}6
public void splitterStop() Li_ a|dI
{ 0dgp<
bStop = true; g"sW_y_O
} 6muZE1sn
,.<l^sj5
;M"JN:J8
} 8wqHr@}p
sP5\R#
QGnBNsAh
/* ajz%3/R
**FileAccess.java &iDX+*(
*//文件访问(定位，写) 9n"D/NZB
package NetFox; H-o>|C
import java.io.*; bR!*z
BHw/~Hd4
;u0MY
public class FileAccessI implements Serializable{ RE(R5n28,
k%)QrRnB
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |};P"&
RandomAccessFile oSavedFile; Jtxwt[
long nPos; t)O$W
D f H>UA
DLv\]\h}L
public FileAccessI() throws IOException .W<yiB}^
{ zviEk/:zm
this("",0); iIoeG_^*Y
} 4c*?9r@
EI*B(
-*u7MFq_
public FileAccessI(String sName,long nPos) throws IOException J ;=~QYn[
{ T8,?\7)S9
oSavedFile = new RandomAccessFile(sName,"rw"); !giL~}j(R
this.nPos = nPos; y pv~F
oSavedFile.seek(nPos); OFTyN^([@
} }Zue?!KQ
I|*w?i*
emo@&6*
public synchronized int write(byte[] b,int nStart,int nLen) tN=B9bm3j
{ R(sPU>`MX
int n = -1; ?6F\cl0.
try{ 7Rf${Wv0
oSavedFile.write(b,nStart,nLen); l#_(suo64
n = nLen; I]|X6
} FDA``H~
catch(IOException e) )Fh+6
{ B`xrdtW
e.printStackTrace (); Fcc\hV;
} |Fk>NX
90oG+T4
xG JX~)
return n; dMw0Aw,2]8
} ]kQ*t{\
+,&8U&~`
0L_JP9e
} O9#8%p% )
_s/5oRHA
v&p|9C@
/* HrH-e=j
**SiteInfoBean.java 5J^S-K^r
*/ 82.::J'e
package NetFox; J|-X?V;ZW
IvFxI#.ju
l&@]
public class SiteInfoBean { B zmmE2~*
A{Jp>15AVg
$^F L*w
private String sSiteURL; //Site's URL UMN3.-4K#
private String sFilePath; //Saved File's Path 3xSt -MA
private String sFileName; //Saved File's Name -\OvOkr
private int nSplitter; //Count of Splited Downloading File C:+-T+m[
\a+.~_iL|
rz%8Vigb
public SiteInfoBean() xx`xDD
{//nSplitter的缺省值为5 y3^<rff3Gc
//default value of nSplitter is 5 mhZ{}~
this("","","",5); 9?5'>WO
} b*w@kLLN
?6;9r[ p
W_:3Sj l'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) v803@9@
{ WZ\bm$
sSiteURL= sURL; A dNQS
sFilePath = sPath; ^=f<WKn
sFileName = sName; WC6yQSnY&
this.nSplitter = nSpiltter; Id6H~;
OIpkXM
*E*= ;BG
} 'aYUF&GG
V\$'3(*
[Yr}:B <
public String getSSiteURL() Wt|IKCx
{ By&T59
return sSiteURL; AgEX,SPP
} 5L6_W-n{
PE $sF]/
i2]7Bf)oV
public void setSSiteURL(String value) pZo:\n5o
{ |]--sUx:
sSiteURL = value; BG>fLp
} -MEp0
|\/`YRg>
gEghDO_G
public String getSFilePath() 00jWs@K
{ Q&j-a;L
return sFilePath; z TYHwx
} +ZFw3KEkz
#m x4pf{
='!E;
public void setSFilePath(String value) muh[wo
{ MI^@p`s
sFilePath = value; tB S+?N
} BlwAD
+,7nsWV
yx0wR
public String getSFileName() PIk2mX/D_6
{ in-|",O`Z
return sFileName; tu5g> qb
} " pg5w
~e|RVY,
}W2FF
public void setSFileName(String value) >A5*=@7bY?
{ 0R2KI,WI
sFileName = value; WC&V9Yk
} <{ZDD]UGs0
ltQo_k
i}u,_ }
public int getNSplitter() (AYzN3 ?D
{ b+=@;0p*6B
return nSplitter; !wbO:py[8>
} O*Gg57a
O`?qnNmc;
(,nQ7,2EX
public void setNSplitter(int nCount) k4N_Pa$}\
{ E?v9c>c
nSplitter = nCount; &`@S_YLr
} 6zyxGJ(
} ]A?(OA
o,r72>|
?04jkq&
/* 5#275Hyv
**Utility.java W;Y"J_
*/ ;$nCQ/ /
package NetFox; 0P_=Oy"l-
/penB[1i
NL^;C3u
public class Utility { kAV4V;ydh
53X i)
u~O9"-m !V
public Utility() ;AH8/M B9
{ .-Z=Aa>
ZVX1@p
B4 k5IS
} 6o:b(v&Oo
$?Km3N\?v
//线程睡眠 fA$2jbGW
public static void sleep(int nSecond) ltWEA
{ L`2(u!i J
try{ t.rlC5 k
Thread.sleep(nSecond); XY`{F.2h
} XWq`MwC9
catch(Exception e) }HCt=W`
{ &0*7]Wo*
e.printStackTrace (); ]D.} /g
} m~I@q [
} q!10G
(X?HuWTm
//日志 !We9T)e
public static void log(String sMsg) *w#^`yeo
{ 9kzJ5}
System.err.println(sMsg); V3S"LJ
} uQhI)
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=L\&}kzB
public static void log(int sMsg) Kj7 ?_o{
{ +B '<0
System.err.println(sMsg); X:#}E7]j
} N,bH@Q.Ci
} 7VIfRN{5n
&q7}HO/ @
Mdw"^x$7
/* ~hxW3e
**TestMethod.java YB+My~fw{l
*/ 2!)|B ;y
package NetFox; [-0=ZKH?
+Pc2`,pw|
H73 r3BH
public class TestMethod { Pk3b#$+E
:@b=;
fKbg?
public TestMethod() j6d{r\!$4
{ ///xx/weblogic60b2_win.exe *snY|hF
try{ %$<v:eMAs
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); r0Zj'F_e
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); C14"lB.
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3o2x&v
fileFetch.start(); 84_Y+_9
} *kt|CXxAS8
catch(Exception e){e.printStackTrace ();} *qA:%m3
<lZVEg
w5+(A_
} v=_Ds<6n
en"\2+{Cg
}U^iVq*
public static void main(String[] args) Xf;_r+;
{ mwMcAUD]2
new TestMethod(); Sa-" G`
} F AQx8P
} k?}y@$[)
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