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)); o5R40["
} U)8]pUI+/P
for(int i=0;i<nEndPos.length-1;i++) O1,[7F.4g
{ 37Y]sJrs$
nEndPos = nStartPos[i+1]; |e>-v
} eH{ 9w8~
nEndPos[nEndPos.length-1] = nFileLength; 6Tnzg`0I
} ]9Hy "#Fz
} Ea?.HRxl
Ags`%(
sd%~pY}
//启动子线程 7/L7L5h<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *_wBV M=2
for(int i=0;i<nStartPos.length;i++) :_*Q IyW
{ 4fswx@l
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Pa<X^&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lH.2H
nStartPos,nEndPos,i); P_U-R%f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d9"4m>ymS
fileSplitterFetch.start(); $}fA;BP
} 2Fi*)\{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~l~g0J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ): 6d_g{2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .>n|#XK
nEndPos = " + nFileLength); bE~lc}%
// fileSplitterFetch[nPos.length-1].start(); k7*q.20
@AOiZOH
QL#y)G53Q
//等待子线程结束 cx}-tj"m-
//int count = 0; k9n93I|Cm
//是否结束while循环 hLRQ)
boolean breakWhile = false; Z]<_a)>
<h({+N
CCV~nf
while(!bStop) Rd)QVEk>SD
{ UZ#2*PH2E
write_nPos(); >YLm]7v}
Utility.sleep(500); v&n&i?
breakWhile = true; g%trGW3{-
3QpTO,
Sls> OIc
for(int i=0;i<nStartPos.length;i++) /Ny&;Y
{ +Sfv.6~v
if(!fileSplitterFetch.bDownOver) e=2D^G#qE
{ F*f)Dv$p
breakWhile = false; ]_s]Q_+E
break; sXu]k#I^"
} YVT^}7#
} DZue.or
if(breakWhile) s><co]
break; AM>:AtY
JFZ p^{
P*>V6SK>b
//count++; 8{C3ijR
//if(count>4) Tx*m p+q
// siteStop(); #82B`y<<y/
} hlRE\YO&8R
Y{KJk'xN5W
-MjRFa
System.err.println("文件下载结束！"); KVuv%?
} 0NxaQ`\
catch(Exception e){e.printStackTrace ();} (Gcl,IW
} ,v"A}g0"
:Lx]`dSk
Zu,f&smb
//获得文件长度 *D,T}N
public long getFileSize() E'Bt1u
{ . fIodk
int nFileLength = -1; a;K:~R+@,
try{ isjkfl-!
URL url = new URL(siteInfoBean.getSSiteURL()); ]l%j>Vb!L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {Fj`'0Xu;
httpConnection.setRequestProperty("User-Agent","NetFox"); G;e}z&6<k
5j]%@]M$Z
_bX)fnUu
int responseCode=httpConnection.getResponseCode(); KjadX&JD
if(responseCode>=400) c\Dv3bF
{ iQKfx#kt
processErrorCode(responseCode); om1 /9
return -2; //-2 represent access is error XL:7$
} *XJSa
rhrlEf@
]Uu/1TTf
String sHeader; )Ii=8etdv
hXCDlCO
D)Zv
for(int i=1;;i++) DCj!m<Y&
{ !>Xx</iD1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); L|<Mtw
//Utility.log(in.readLine()); {'1,JwSmb
sHeader=httpConnection.getHeaderFieldKey(i); <6@Db$-
if(sHeader!=null) $Ix^Rm9c
{ }^H_|;e1p
if(sHeader.equals("Content-Length")) *b&|
{ 7%hMf$KQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sdb#K?l
break; g0l- n
} 9;PtYdJ8
} xRfX:3
else 2h=RNU|
break; wNlp4Z'[
} fRiHs\+
} IoC,\$s,
catch(IOException e){e.printStackTrace ();} [K5afnq`
catch(Exception e){e.printStackTrace ();} B-RaAiE@
>(3y(1;
{S?.bT%&
Utility.log(nFileLength); W+QI D/
DD1S]m
{0?76|
return nFileLength; %:NI@59
} V{][{5SR
1peN@Yk2W
'>Z Ou3>
//保存下载信息（文件指针位置） Q]8r72uSk
private void write_nPos() OA_ %%A;o
{ fIu/*PFPVY
try{ u7S7lR"lxW
output = new DataOutputStream(new FileOutputStream(tmpFile)); (j(6%U
output.writeInt(nStartPos.length); R7#B_^ $
for(int i=0;i<nStartPos.length;i++) J&Ah52
{ n}"MF>zDK
// output.writeLong(nPos); +p2)uXqW
output.writeLong(fileSplitterFetch.nStartPos); hQ9VcS6=gD
output.writeLong(fileSplitterFetch.nEndPos); j:0z/gHp$
} `sSI;+
output.close(); k]Yd4CC2
} E11"uWk`
catch(IOException e){e.printStackTrace ();} CGQ`i
catch(Exception e){e.printStackTrace ();} NOvN8.K%
} .A E(D7d6
\n}cx~j
[,VD^\
//读取保存的下载信息（文件指针位置） |g~.]2az
private void read_nPos() nk[ixVc
{ zJPzI{-w|
try{ \QVL%,.%M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5( 3tPbm{
int nCount = input.readInt(); ).\%a h
nStartPos = new long[nCount]; `,J\E<4J
nEndPos = new long[nCount]; L9T|*?||
for(int i=0;i<nStartPos.length;i++) u BvN*LQ
{ Kg56.$
nStartPos = input.readLong(); 2vynz,^ET
nEndPos = input.readLong(); 4v;/"4)'
} 7v{Dwg
input.close(); >y5~:L
} ct`89~"
catch(IOException e){e.printStackTrace ();} jVr:O`
catch(Exception e){e.printStackTrace ();} =m UtBD.;
} A," u~6Bn
cY5h6+_
<%!EI@N
private void processErrorCode(int nErrorCode) {Wt=NI?Ow
{ 7"1M3P5*8
System.err.println("Error Code : " + nErrorCode); gkDB8,C<j
} f|u!?NGl
}5EvBEv-)
<d8Yk>R
//停止文件下载 i6aM}p<
public void siteStop() F.4xi+S_
{ C-&\qAo?<:
bStop = true; i!(u4wTFF
for(int i=0;i<nStartPos.length;i++) Tv!zqx#E
fileSplitterFetch.splitterStop(); P9BShC5
RK< uAiU
>HyZ~M
} V3 2F
} $/K<hT_
//负责部分文件的抓取 ?g}G#j
**FileSplitterFetch.java ,VI2dNst\
*/ 6YNd;,it>p
package NetFox; L\aG.\
}gete'I
r[K%8Y8`
import java.io.*; W|4:3c4
import java.net.*; R10R,*6>
;O+= 6>W
nH_M#
public class FileSplitterFetch extends Thread { qf;x~1efC4
2)-Umq{]{
|cs]98FEf
String sURL; //File URL 9!;/+P
long nStartPos; //File Snippet Start Position @P@?KZ..v!
long nEndPos; //File Snippet End Position PKJw%.-
int nThreadID; //Thread's ID dSkMA
boolean bDownOver = false; //Downing is over }"Clv/3_
boolean bStop = false; //Stop identical ;X, A|m$(
FileAccessI fileAccessI = null; //File Access interface 3s;^p,9 Y
*mby fu0q
;?4EVZ#o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %py3fzg
{ T,r?% G{XE
this.sURL = sURL; shKTj5s?
this.nStartPos = nStart; $Y,y~4I
this.nEndPos = nEnd; h/k00hD60
nThreadID = id; xPCRT*Pd
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T\q:
} 9eBD)tnw
>P@g].Q-
a5caryZ"z
public void run() r'8qZJgm
{ HAwdu1$8
while(nStartPos < nEndPos && !bStop) a`I \19p]
{ XlLG/N
a@!(o )>
o, PpD,,
try{ ?.Q$@Ih0
URL url = new URL(sURL); {>g{+Eq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ia@ |+r
httpConnection.setRequestProperty("User-Agent","NetFox"); Z-:T')#Cf
String sProperty = "bytes="+nStartPos+"-"; @CMEmgk~
httpConnection.setRequestProperty("RANGE",sProperty); "zj[v1K9-A
Utility.log(sProperty); T[Lz4;TRk5
[n4nnmM
Wz%H?m:g#
InputStream input = httpConnection.getInputStream(); jh(T?t$&
//logResponseHead(httpConnection); jIEntk
G>=Fdt7Oc
nr&bpA/
byte[] b = new byte[1024]; ox*1F+Xri
int nRead; .J<t]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0CO@@`~4
{ ml@;ngmp.
nStartPos += fileAccessI.write(b,0,nRead); `J]e.K
//if(nThreadID == 1) u8.F_'`z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _AzI\8m
} .do8\
~[%_]/#&%z
ncqAof(/
Utility.log("Thread " + nThreadID + " is over!"); AXF 1{
bDownOver = true; /%g+|C
//nPos = fileAccessI.write (b,0,nRead); bmu]zJ
} _o[fjd
catch(Exception e){e.printStackTrace ();} pT{is.RM
} :{+~i.*
} ^hXm=r4ozR
KRz~3yH{c
wx^Det
//打印回应的头信息 hC[=e`j
public void logResponseHead(HttpURLConnection con) ]VL} eHZ
{ Z_[ P7P
for(int i=1;;i++) 4%2APvLW
{ , #=TputM
String header=con.getHeaderFieldKey(i); 9#TD1B/
if(header!=null) @R%*;)*F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); tn#cVB3
Utility.log(header+" : "+con.getHeaderField(header)); r0!')?#Z
else f0vO(@I
break; #9gx4U
} 793 15A
} >TMd1?,
)$RV)
d?&`ZVl
public void splitterStop() .W^B(y(tA
{ /78]u^SW
bStop = true; ((C|&$@M
} M!+J[q
?z`={oN
oUwo!n}
} 3_<l`6^Ns/
,`JYFh M
sC.b'1P
/* Q7rBc wm5
**FileAccess.java qCg<g
*//文件访问(定位，写) D'<L6w`
package NetFox; R\|,GZ!`+
import java.io.*; 1~t.2eUG
]XU4nNi
4j~q,#$LW
public class FileAccessI implements Serializable{ Q66 +
cef[T(>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +N=HI1^54R
RandomAccessFile oSavedFile; "]#Ij6ml
long nPos; t5%cpkgh4
("\{=XAQ
s]%Cz\
public FileAccessI() throws IOException ]f#s`.A~
{ L/Q[N^ (^
this("",0); o!:Z?.!
} 1l$2T y+ =
sEFQ8S
@QV0l]H0+
public FileAccessI(String sName,long nPos) throws IOException *#'j0;2F
{ kL%ot<rt)w
oSavedFile = new RandomAccessFile(sName,"rw"); 0CX,"d_T,
this.nPos = nPos; ]o8]b7-
oSavedFile.seek(nPos); &y5"0mA
} ?OLd }8y
M2Jf-2
g35!a<JW
public synchronized int write(byte[] b,int nStart,int nLen) Vf;&z$D{r
{ ka~_iUU4
int n = -1; 0K[]UU=P=
try{ BbI%tmA7
oSavedFile.write(b,nStart,nLen); kzKej"a;
n = nLen; Ec!!9dgRQ
} S7)qq
catch(IOException e) U3X5tED
{ EW|$qLg
e.printStackTrace (); ao2^3e
} /QY F|%7!
iqvLu{
S[1<Qrv]
return n; hE|P|0U,n
} .Q%Hi7JMi
,c4HicRJ#
aOH|[
} ^K;k4oK
EY)2,
ZU73UL
/* g%&E~V/g$
**SiteInfoBean.java >E>yA d
*/ HEBeJ2w
package NetFox; q7X#LYk
@khFk.LBD
{1)A"lQu
public class SiteInfoBean { w}gmVJ#p
`Gqe]ZE#"
<Z]#vrq
private String sSiteURL; //Site's URL -B;#pTG
private String sFilePath; //Saved File's Path SLKplLO
private String sFileName; //Saved File's Name Wd:pqhLh
private int nSplitter; //Count of Splited Downloading File +4s]#{mP
$Z:O&sD{
2)n`Bd
public SiteInfoBean() o]4]fLQ
{//nSplitter的缺省值为5 x~V[}4E%>
//default value of nSplitter is 5 rP:g`?*V
this("","","",5); ,WRm{v0f^
} LqbI/AQ)
vkIIuNdDlx
&"^F;z/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ca|egQv
{ E+aePoU
sSiteURL= sURL; S"cTi[9
sFilePath = sPath; L}`/v]E"eU
sFileName = sName; *4}_2"[
this.nSplitter = nSpiltter; Co1d44Q
VBX)xQazU
M]s\F(*ib
} pR61bl)
wtw=RA
w"v!+~/9
public String getSSiteURL() r{;NGQYs
{ g&s. 0+
return sSiteURL; N1$u@P{
} ,^:{!?v
n93q8U6m/U
?{ N,&d
public void setSSiteURL(String value) IrMHAM5K
{ >Uw:cq
sSiteURL = value; )0VL$A
} 'z ?Hv
x4WCAqi/2
cUY-
public String getSFilePath() iFd !ED
{ { ADd[V
return sFilePath; 'z$$ZEz!C
} F\m^slsu7=
z`wIb
Zw]"p63eMa
public void setSFilePath(String value) 6:zPWJB
{ JOJ.79CT
sFilePath = value; XQo\27Fo
} ;|q<t
C?\(?%B
\O5L#dc#
public String getSFileName() Anz{u$0M[
{ qYK^S4L
return sFileName; MgXZN{
} Tn&_ >R
#`VAw ) eV
MTu\T
public void setSFileName(String value) 8ymdg\I+L
{ BJjic%V
sFileName = value; ,"EaZ/Bl/
} 2lTt
(!* l+}
]l,D,d81
public int getNSplitter() "^#O7.oVi+
{ "`qk}n-
return nSplitter; l77 -I:
} =A'>1N
b j&!$')
2FMmANH0ev
public void setNSplitter(int nCount) riIubX#
{ 0~U#DTx0
nSplitter = nCount; \D@j`o
} Z[#8F&QV!m
} Z)7{~xq
&qx/ZT
9hzu!}~'I
/* Nf| 0O\+%y
**Utility.java 9^a|yyzL
*/ Jh-yIk
package NetFox; E=I'$*C\D
bBi>BP=
%p 6Ms
public class Utility { s~Eo]e
k=s^-Eiu
Wd'}YbC
public Utility() vFUp$[
{ k-~}KlP
f Fi=/}
Xh8U}w<k6
} SoziFI
G<CD4:V
//线程睡眠 #:?:gY<
public static void sleep(int nSecond) BZ?w}%-MO
{ JN8Rh
try{ aT,WXW*
Thread.sleep(nSecond); c}@E@Y`@w
} I'5[8
catch(Exception e) sX"L\v
{ ntIR#fB
e.printStackTrace (); /dCsZA
} ~cm4e>o
} $n<1D -0!r
-b!?9T?}
//日志 RvR.t"8
public static void log(String sMsg) #N][-i
{ #6M |T+=
System.err.println(sMsg); L(3&,!@
} "]eB2k_>
T6/P54S
U6-47m0%
public static void log(int sMsg) Mi.#x_
{ &b (*
System.err.println(sMsg); /`M#
} e#oK% {A
} ]WMzWt:L
"mn?*
Z66Xj-o
/* 3HyOQD"{
**TestMethod.java QvbH " 7
*/ "}X+vd``
package NetFox; /4+L2O[
.s\lfBo9
2*sTU
public class TestMethod { &<><4MQ
a<-aE4wdm
_n:RA)4*
public TestMethod() >a975R*g
{ ///xx/weblogic60b2_win.exe \:@6(e Bh
try{ Wrp~OF0k
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p-j6H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +&\. ]Pp
SiteFileFetch fileFetch = new SiteFileFetch(bean); N_92,xI#
fileFetch.start(); {`):X_$T
} mX>N1zAz
catch(Exception e){e.printStackTrace ();} #j Tkz
S:{xx`6K
*$O5.`]
} 5@RcAQb:
(c0L@8L
&Sg]P
public static void main(String[] args) T @^ S:K
{ %f<>Kwr`2
new TestMethod(); 2=?3MXcjy
} fln[Q2zl
} w7`pbcY,
点击下载更多相关资料