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)); *T5!{
} i70wrW#k
for(int i=0;i<nEndPos.length-1;i++) ]=>F.GE
{ . koYHq
nEndPos = nStartPos[i+1]; \'|>p/5I
} i[?Vin
nEndPos[nEndPos.length-1] = nFileLength; >AcrG]
} ^-,xE>3o
} V+VkY3
4<k9?)~(J
/+@p7FqlE
//启动子线程 }Q=!Y>Tc
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dvt9u9Vg=
for(int i=0;i<nStartPos.length;i++) T3k#VNH
{ vvKEv/pN7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y?(r3E^x
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iZM+JqfU|D
nStartPos,nEndPos,i); hFH*B~*:#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !*oi!ysU;O
fileSplitterFetch.start(); QNpqdwu%h
} S/4^ d &Gr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QWzB6H]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Sgp;@4`M
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", px}|Mu7z~
nEndPos = " + nFileLength); aB7+Tb
// fileSplitterFetch[nPos.length-1].start(); ][?G/*k
Ry%Mej:
.6`9H 1
//等待子线程结束 @wE5S6! B\
//int count = 0; (X?%^^e!
//是否结束while循环 4}4Pyjh
boolean breakWhile = false; A29gz:F(
&NH$nY.r
m]5Cq6
while(!bStop) F.w5S!5Q
{ .HkL2m
write_nPos(); FW/W%^
Utility.sleep(500); STxKE %l
breakWhile = true; 9J9)AV
fjs [f'L
Q\ U:~g3
for(int i=0;i<nStartPos.length;i++) iZaI_\"__
{ !f&Kf,#b`
if(!fileSplitterFetch.bDownOver) :=wTvz
{ N4L|;?
breakWhile = false; ^eR%N8Z
break; h-Fn?
} >(?9?
} hvDNz"ec{
if(breakWhile) `kZ@Zmj#
break; 3td)'}
]dI2y=[!C
}^/9G17
//count++; c@/(B:@
//if(count>4) ni<A3OB
// siteStop(); E}40oID
} ;9#Z@]p
ev#;t@^
V&Xe!S
System.err.println("文件下载结束！"); -3;*K4z$/
} V-Cv,8
catch(Exception e){e.printStackTrace ();} .zn;:M#T
} Db;G@#x
YRh BRE
;S57w1PbVA
//获得文件长度 m6',SY9T
public long getFileSize() 1DvR[Lx%
{ p' +
int nFileLength = -1; ds?v'|
try{ lJE93rXU
URL url = new URL(siteInfoBean.getSSiteURL()); YEj8S5"Su\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); X!m9lV<
httpConnection.setRequestProperty("User-Agent","NetFox"); 20Z8HwQi
b#K:_ac5
qL6 |6-?
int responseCode=httpConnection.getResponseCode(); Y@b.sMg{
if(responseCode>=400) l)!n/x_ !
{ 8erSt!oM
processErrorCode(responseCode); !!`!|w
return -2; //-2 represent access is error 't6V:X
} /)4I|"}R0I
_g~qu [1
|b|&XB_<]Z
String sHeader; )*,5"CO
k[HAkB \{
xYhrO
for(int i=1;;i++) brdmz}
{ 0 0M@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); `.x Fiyc
//Utility.log(in.readLine()); A@sZ14+f
sHeader=httpConnection.getHeaderFieldKey(i); 4Qo]nre!
if(sHeader!=null) R +WP0&d'
{ ,B0_MDA +
if(sHeader.equals("Content-Length")) unBy&?&p
{ *7h!w!LN~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Up,vD)tG
break; D,g1<:<
} nSkPM5\TI
} qUOKB6
else C@bm
break; o]p|-<I Q
} |Tm!VFd
} DBT&DS
catch(IOException e){e.printStackTrace ();} ^9ePfF)5
catch(Exception e){e.printStackTrace ();} F$hYKT2|
LWHd~"eU
qHP78&wUx
Utility.log(nFileLength); ^",ACWF4Sk
|jVM&R2s
=Q[b'*o7
return nFileLength; Nqrmp" ]
} 1f8GW
-tyK~aasQ
4=Krq6{
//保存下载信息（文件指针位置） H8`(O"V
private void write_nPos() TH$N5w%
{ i}o[- S4
try{ ]@0NO;bK>F
output = new DataOutputStream(new FileOutputStream(tmpFile)); :P@rkT3Qt
output.writeInt(nStartPos.length); ]- 4QNc=
for(int i=0;i<nStartPos.length;i++) NsJ(`zk:
{ *0>mB
// output.writeLong(nPos); !}r% u."
output.writeLong(fileSplitterFetch.nStartPos); NN1$'"@NL
output.writeLong(fileSplitterFetch.nEndPos); 6+KHQFb&N
} {FG|\nPw
output.close(); EoxQ */
} e&qh9mlE
catch(IOException e){e.printStackTrace ();} E4W zU
catch(Exception e){e.printStackTrace ();} LbZ:&/t^y8
} w&B#goS
]<q[Do8k
qg}O/K
//读取保存的下载信息（文件指针位置） *L'>U[Pl7
private void read_nPos() jD`d#R
{ *r$+&8V\n
try{ _!?Hu/zo
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); GR"Eas.$
int nCount = input.readInt(); f4guz
nStartPos = new long[nCount]; kr9gK~
nEndPos = new long[nCount]; `UQf2o0%3w
for(int i=0;i<nStartPos.length;i++) pmFk50`
{ +ke1Cn'[
nStartPos = input.readLong(); *mMEl]+
nEndPos = input.readLong(); W!"}E%zx
} MiRdX#+Y
input.close(); x"CZ]p&m
} o)[2@fRC(
catch(IOException e){e.printStackTrace ();} \C`~S7jC
catch(Exception e){e.printStackTrace ();} ryc& n5
} pOrWg@<\L
yH<$k^0r*
EgDQ+( -
private void processErrorCode(int nErrorCode) -#Z bR
{ WzI8_uM
System.err.println("Error Code : " + nErrorCode); W{rt8^1
} &%_& 8DkG
@j4U^"_QB
Eb=#9f%y>&
//停止文件下载 jh.@-
public void siteStop() kee|42E
{ f7'q-
bStop = true; D Kw*~0
for(int i=0;i<nStartPos.length;i++) j$7Xs"
fileSplitterFetch.splitterStop(); F|HJH"2*&q
6O22P?v
\J6hI\/4^
} |/|
} `WOYoec
//负责部分文件的抓取 yj$TPe_BW
**FileSplitterFetch.java ,.o<no
*/ U7DCx=B
package NetFox; DtEwW1J
$L2%u8}8:
nxJee=qH
import java.io.*; o8Z[+;
import java.net.*; B=@ jWz"
wHem5E
;kJu$U
public class FileSplitterFetch extends Thread { 2Gs$?}"a
@y/wEBb
//&j<vus
String sURL; //File URL N7s'6(`=X
long nStartPos; //File Snippet Start Position Jz!Z2c
long nEndPos; //File Snippet End Position ,o7hk{fR*
int nThreadID; //Thread's ID lMz<s
boolean bDownOver = false; //Downing is over !P$'#5mr
boolean bStop = false; //Stop identical (?*BB3b`
FileAccessI fileAccessI = null; //File Access interface ~kCwJ<E
& ``d
l6u&5[C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _NcYI
{ oiH|uIsqR
this.sURL = sURL; #DjCzz\
this.nStartPos = nStart; /S\cU`ZVe
this.nEndPos = nEnd; AC.A'|"]i
nThreadID = id; dk==?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1,V`8 [
} Zh/Uu6
e62Dx#IY
k5&bq2)I
public void run() \Yoa:|%*y
{ sIl33kmv
while(nStartPos < nEndPos && !bStop) w~@-9<^K]v
{ (.Lrmf@hI7
lZQ/W:OE
$oLU; q%
try{ %ObD2)s6:^
URL url = new URL(sURL); 3[XQR8o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h)v^q: ='
httpConnection.setRequestProperty("User-Agent","NetFox"); Oc&),ru2l
String sProperty = "bytes="+nStartPos+"-"; v[lnw} =m9
httpConnection.setRequestProperty("RANGE",sProperty); &-1./?
Utility.log(sProperty); @wq#>bm
e0;
xc?}TPpt
InputStream input = httpConnection.getInputStream(); t+nRw?Z
//logResponseHead(httpConnection); w18RA#Zo/
9Z6C8Jv
dP>w/$C}
byte[] b = new byte[1024]; IF@HzT;Q
int nRead; &l}?v@@+_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I@l>w._.
{ D0;tcm.$
nStartPos += fileAccessI.write(b,0,nRead); rQP"Y[
//if(nThreadID == 1) @:x"]!1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q!M)xNl/
} *wV[TKaN
)nu~9km3
F8+e,x
Utility.log("Thread " + nThreadID + " is over!"); s^T+5E&}
bDownOver = true; E-1"+p
//nPos = fileAccessI.write (b,0,nRead); \nqo%5XL
} &gc`<kLu
catch(Exception e){e.printStackTrace ();} hFvi5I-b
} !CjqL~
} \Z/k;=Sla
ZB5?!.ND
MF[z-7
//打印回应的头信息 jK8'T_Pah
public void logResponseHead(HttpURLConnection con) +dkS/b
{ ?G?gy2
for(int i=1;;i++) !6w{(Rc(C
{ 0W>9'Rw
String header=con.getHeaderFieldKey(i); MjaUdfx
if(header!=null) {Ts:ZI+ 8d
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ^^(<c,NX#M
Utility.log(header+" : "+con.getHeaderField(header)); ;5<-)
else 2:$ k
break; uG>nV
} gUB{Bh($Y
} K%}}fw2RMN
Y(GN4@`S
|xr32gs
public void splitterStop() i9UI,b%X
{ ' eO/PnYW
bStop = true; CsSp=(
} -cNx1et
gY`Nr!O
U '[?9/T
} 1h"_[`L'
#/j={*-
Fu8 7fVi/\
/* }gsO&g"8
**FileAccess.java "uu)2Xe
*//文件访问(定位，写) iilyw_$H
package NetFox; X9~m8c){z
import java.io.*; wVi%oSfM
oTOfK}
9u wL{P&
public class FileAccessI implements Serializable{ U |F>W~%
SZVV40w
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "E*8h/4u
RandomAccessFile oSavedFile; {U <tc4^
long nPos; rbk<z\pc
!Y;<:zx5
"+iAd.qd
public FileAccessI() throws IOException {Iy7.c8S
{ ^i<}]c_|f
this("",0); ;mO,3dV
} L(WOet('
_g6m=N4
Sb^ b)q"
public FileAccessI(String sName,long nPos) throws IOException gJ\%>r7h
{ Ugi5OKdj7)
oSavedFile = new RandomAccessFile(sName,"rw"); RT"O;P
this.nPos = nPos; +0pW/4x
oSavedFile.seek(nPos); PW_`qP:
} $(>f8)Uku(
I^fPk
-[.PH M6+?
public synchronized int write(byte[] b,int nStart,int nLen) TC-f%1(
{ GhnE>d;i
int n = -1; X*Z5 P
try{ J5T=!wF (
oSavedFile.write(b,nStart,nLen); ]+IVSxa!u
n = nLen; "2h5m4
} A9BxwQU#
catch(IOException e) @;9()ad
{ xbC~C~#
e.printStackTrace (); *1;23BiH-
} #J+\DhDEPO
uFe'$vI
|t\KsW
return n; ci7~KewJ*
} _hoAW8i
ida*]+ ~
11*"d#
} |h1^Gv
tL8't]M,
spiDm:Xe
/* P$h;SK
**SiteInfoBean.java -fM1$/]
*/ }W "(cYN_
package NetFox; h}6b&m
TczXHT}G
GUCM4jVT^
public class SiteInfoBean { fI[dhd6
r"]Oe$[#
z1vni'%J
private String sSiteURL; //Site's URL 4? {*(
private String sFilePath; //Saved File's Path -~'kP /E^
private String sFileName; //Saved File's Name a97Csxf;7
private int nSplitter; //Count of Splited Downloading File &^ceOV0+
=[(%n94
&9h
public SiteInfoBean() n49s3|#)G
{//nSplitter的缺省值为5 f)tc4iV
//default value of nSplitter is 5 t/LgHb:)
this("","","",5); 7sN0`7
} w?;b7i
1OPfRDn.bk
8g5.7{ky
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) !'PlDGD
{ QAXYrRu
sSiteURL= sURL; 7+S44)w}~
sFilePath = sPath; Lnx2xoNk
sFileName = sName; 2^bgC~2C1
this.nSplitter = nSpiltter; ./!KE"!
^=#!D[xj>
q/J3cXa{K
} (v|`LmV
f}-v
"sIN86pCs
public String getSSiteURL() ypT9 8
{ &O{t^D)F
return sSiteURL; d:3= 1x
} <|dj^.^
J<-Fua^
WV~SL/k|
public void setSSiteURL(String value) HtS#_y%(
{ cB36p&%
sSiteURL = value; .6I%64m
} G%`cJdM
V"U~Q=`K
`NoCH[$!+
public String getSFilePath() I9:%@g]uYw
{ Z[bv0Pr
return sFilePath; ,m"l\jP
} " V/k<HRw
_6/Qp`s
R_~F6O^EO
public void setSFilePath(String value) fcn_<Yh0W
{ bF7`] 83
sFilePath = value; gTyW#verh$
} sK[Nti0
0Sz/c+ 6
:!hk~#yvJ9
public String getSFileName() DMRs}Yz6
{ vy:6_
return sFileName; ~CJYQFt
} s!=!A
}K+\8em
~JT lPU'
public void setSFileName(String value) >d)|r
{ _qk9o
sFileName = value; rcpvH}N:
} /.f!
?~]>H A:
}"g@E-]N
public int getNSplitter() dfXV1B5
{ 2voNgY
return nSplitter; Z^C!RSQ
} cRPr9LfD@
u'{sB5_H
5@""_n&FV
public void setNSplitter(int nCount) d?E4[7<t$1
{ EywZIw?mjX
nSplitter = nCount; rHR5,N:
} CcbWW4 )
} PwRNBb}6
s')!<E+z\t
\y<+Fac1S
/* pq@$&G
**Utility.java w2s,
*/ >l6XZQ >
package NetFox; &<m WA]cAL
RNsJ!or
Q9SPb6O2
public class Utility { ]eORw$f
Ynv 9v\n|
vs*_;vx
public Utility() A/r;;S)%2
{ VK"[=l
dVK@Fgo
zX006{vig
} Ebmqq#SHjX
!<JG&9ODP
//线程睡眠 ^$3w&$K*
public static void sleep(int nSecond) a^(S!I
{ 8j({=xbg&
try{ i,\t]EJAU
Thread.sleep(nSecond); >!CH7wX
} mOgx&ns;j
catch(Exception e) N}e(.
{ IiQWs1
e.printStackTrace (); Yf%[6Y{
} 2-/YYe;C
} ZhxfI?i)l
=rE`ib
//日志 0`zm>fh}
public static void log(String sMsg) JB:mbH
{ bt.K<Y0
System.err.println(sMsg); K.c6Rg
} Fvcq^uZ
>V77X+!
~6pCOS}
public static void log(int sMsg) &ij^FAM
{ h=mI{w*
System.err.println(sMsg); J:k@U42
} V_ avaE
} \:18Uoe7
"y3dwSS
EC:x,i
/* sP=2NqU3Q
**TestMethod.java BUboP?#%)
*/ $]`'Mi
package NetFox; H znI R
$/-wgyP3m+
gDjd{+LUo
public class TestMethod { @vDgpb@TM
1-ndJ@Wlz
c9/ 'i
public TestMethod() cftn`:(&8
{ ///xx/weblogic60b2_win.exe !~VR|n-
try{ mDe+ M{/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -+Awm{X_@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3w6JV+?
SiteFileFetch fileFetch = new SiteFileFetch(bean); `"1{Sx.
fileFetch.start(); S(YHwH":
} lu9Ir>c
catch(Exception e){e.printStackTrace ();} U(=f5|-
(&a3v
\5v=pDd4g
} $e^ :d
M2;(+8 b
J,&`iL-
public static void main(String[] args) ) J:'5hz
{ K{7S
new TestMethod(); .LhbhUEfn
} D[FfJcV'$
} A,A-5l<h]?
点击下载更多相关资料