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)); #J, `a.
} JdfjOlEb
for(int i=0;i<nEndPos.length-1;i++) 9W5vp:G
{ E{_p&FF
nEndPos = nStartPos[i+1]; jv5p_v4%O
} u(\b1h n
nEndPos[nEndPos.length-1] = nFileLength; +<Uc42i7n
} .?[2,4F;
} ^B1Q";# B^
B<H5WI
}a'8lwF%I
//启动子线程 ]. IUQ*4t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /"~CWNa
for(int i=0;i<nStartPos.length;i++) U:#9!J?41
{ mUm9[X~'
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @;G}bYq^(I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (4>k+ H
nStartPos,nEndPos,i); j Bl I^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zK}$W73W^
fileSplitterFetch.start(); !HY+6!hk
} 1$q SbQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x a7x 2]~-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 06]J]
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 0{@E=}}h
nEndPos = " + nFileLength); Hp8)-eT
// fileSplitterFetch[nPos.length-1].start(); [9Q2/V;Uk%
&f|LjpMCf
yg5Ik{
//等待子线程结束 Xi6XV3G
//int count = 0; |bO}|X
//是否结束while循环 S$=])^dur
boolean breakWhile = false; QApil
]p `#KVW
L/F!Y%=;[
while(!bStop) ql2>C.k3L
{ m.&z:`x[
write_nPos(); 3EI$tP@4
Utility.sleep(500); wg<DV!GZ
breakWhile = true; b_|`jHes
>(|T]u](q
W-<C%9O!
for(int i=0;i<nStartPos.length;i++) t1 OnA#]/_
{ *<i { Mb Q
if(!fileSplitterFetch.bDownOver) vc^qpOk
{ @@# ^G8+l
breakWhile = false; va:5pvt2&
break; ]pzf{8%
} f]qPxRw
} Zyu4!
if(breakWhile) Eii)zo8Xd
break; KWLI7fTgj$
TXv3@/>ZlG
q#xoM1
//count++; GASDkVoij
//if(count>4) >j4;{r+eQw
// siteStop(); fx_7X15
} _<+!
.Lr;{B
x<>#G~-
System.err.println("文件下载结束！"); P bj&l0C
} D2#3fM6
catch(Exception e){e.printStackTrace ();} YiTiJ9jf
} \3"4;fM!i
;*BG{rkr
T[`o$j6
//获得文件长度 fk<0~tE
public long getFileSize() 9G[!"eZ}
{ 7YV}F9h4
int nFileLength = -1; rUc2'Ct
try{ eBFsKOtu
URL url = new URL(siteInfoBean.getSSiteURL()); %|*tL7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); H!y1&
httpConnection.setRequestProperty("User-Agent","NetFox"); _rdEur C6
[6`8^-}?
^a0{"|Lq
int responseCode=httpConnection.getResponseCode(); CCNrjaA
if(responseCode>=400) E].hoq7WiB
{ ]]Sz|6P
processErrorCode(responseCode); %?Yf!)owh
return -2; //-2 represent access is error ,,sKPj[
} 6U Q~Fv`]
,6=j'j1#a
M2W4 RovfR
String sHeader; 9{RCh9
_ho9}7 >
J/mLmSx
for(int i=1;;i++) 9. 6"C<eYt
{ )\s{\u \
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); C< 3`]l
//Utility.log(in.readLine()); g`i?]6c}jt
sHeader=httpConnection.getHeaderFieldKey(i); F{WV}o=MY
if(sHeader!=null) <wfPbzs-V
{ }^+E S^~
if(sHeader.equals("Content-Length")) QbjO*:c4
{ LUc!a4i"fO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Za_w@o
break; CBN,~wzP*
} ,bzE`6
} 84j6.\,
else pX8TzmIB0
break; `|)V]<
} ?12[8
} ^hr^f;N
catch(IOException e){e.printStackTrace ();} (HbA?Aja
catch(Exception e){e.printStackTrace ();} 9AF%Y:y
-N $4\yp
:[xFp}w{
Utility.log(nFileLength); <'N"GLJ
}$iKz*nx|
mhVdsa
return nFileLength; [1nfSW
} o-a\T
d0``:
8JYU1Ew
//保存下载信息（文件指针位置） :d}I`)&
private void write_nPos() .;}vp*
{ UCV1{
try{ !k@(}CN_*
output = new DataOutputStream(new FileOutputStream(tmpFile)); GVR/p
output.writeInt(nStartPos.length); QiC}hj$
for(int i=0;i<nStartPos.length;i++) ]s_,;PGU
{ ]dIcW9a
// output.writeLong(nPos); bca4'`3\|
output.writeLong(fileSplitterFetch.nStartPos); ;}1O\nngR
output.writeLong(fileSplitterFetch.nEndPos); /|Z_Dy
} o1lhVM`15
output.close(); ) rw!. )
} TS4Yzq,f
catch(IOException e){e.printStackTrace ();} lt08 E2p9
catch(Exception e){e.printStackTrace ();} 0"}qND
} dyWj+N5(
CGw,RNV
#djby}hi
//读取保存的下载信息（文件指针位置） A\ARjSdb
private void read_nPos() '^B[Krs'Z`
{ Cq8.^=}_
try{ 8! eYax
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RGEgYOO
int nCount = input.readInt(); 7}#zF]vHNi
nStartPos = new long[nCount]; B^Sxp=~Au
nEndPos = new long[nCount]; Gk:tT1
for(int i=0;i<nStartPos.length;i++) W%@r
{ Z<D8{&AjS
nStartPos = input.readLong(); ['m7Wry
nEndPos = input.readLong(); w3Lr~_j
} C(CwsdlP
input.close(); Fz11/sKz
} IC"Z.'Ph
catch(IOException e){e.printStackTrace ();} :3b.`s(M
catch(Exception e){e.printStackTrace ();} {ooztC
} Mc,3j~i
2ieyU5q7#
^?J3nf{
private void processErrorCode(int nErrorCode) C&|K7Zp0v
{ "w&IO}j;=
System.err.println("Error Code : " + nErrorCode); n)|{tb^
} 7f] qCZ<0V
hKnAWKb0
%lq[,6?>5
//停止文件下载 9Js+*,t
public void siteStop() w)N~u%
{ 9U>OeTh(
bStop = true; ONVhB
for(int i=0;i<nStartPos.length;i++) y%Rq6P=4Q
fileSplitterFetch.splitterStop(); hsB3zqotF
`%A vn<
R_W6}
} :W^\ }UX4
} CY~ S{w
//负责部分文件的抓取 1-V"uLy@gC
**FileSplitterFetch.java D*&#}c,*
*/ hT`fAn_
package NetFox; tm&,u*6$W?
S86,m=
`L LS|S]
import java.io.*; .af+h<RG4$
import java.net.*; ZyM7)!+kPa
r=-b@U.fk>
Ptm=c6H('
public class FileSplitterFetch extends Thread { A!cY!aQ
:6MV@{;PJ
j"hNkCF
String sURL; //File URL a8$4
long nStartPos; //File Snippet Start Position NX4G;+6
long nEndPos; //File Snippet End Position c=,HLHpFO(
int nThreadID; //Thread's ID Al1_\vx7
boolean bDownOver = false; //Downing is over ]ur?i{S,
boolean bStop = false; //Stop identical {p.^E5&
FileAccessI fileAccessI = null; //File Access interface ]"/SU6#4:
E+ctiVL
B"YN+So
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nW)?cQ I
{ A+|bJ>q
this.sURL = sURL; dGgltY
this.nStartPos = nStart; 8WE@ X)e
this.nEndPos = nEnd; EXMW,
nThreadID = id; Q6T"8K/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QJ&]4*>a
} STl8h}C
7Kf
:wq][0)
public void run() >AFQm
{ <Drm#2x!E
while(nStartPos < nEndPos && !bStop) I cASzSjYX
{ m%0_fNSJ
5tyA{&Ao
$K.DLqDt
try{ D]o=I1O?
URL url = new URL(sURL); 6f2?)jOW^N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -T}r$A
httpConnection.setRequestProperty("User-Agent","NetFox"); 15@2h
String sProperty = "bytes="+nStartPos+"-"; r+8)<Xt+p
httpConnection.setRequestProperty("RANGE",sProperty); yAAV,?:o[
Utility.log(sProperty); 5o0n4W
#SKC>MGz
mv>0j<C91
InputStream input = httpConnection.getInputStream(); mPU}]1*p
//logResponseHead(httpConnection); Zs(BViTb|
IsmZEVuC
NE.h/+4
byte[] b = new byte[1024]; v%$l(
int nRead; ht*N[Pi4;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g$ HL::
{ @0]w!q
nStartPos += fileAccessI.write(b,0,nRead); 0C;Js\>3]
//if(nThreadID == 1) 8 :WN@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -RJ~Sky[
} (/At+MF3E
^vxx]Hji
BTD_j&+(
Utility.log("Thread " + nThreadID + " is over!"); EnGh&]
bDownOver = true; &\I<j\F2/
//nPos = fileAccessI.write (b,0,nRead); m.rV1#AI
} B`.aQ
catch(Exception e){e.printStackTrace ();} [(2^oTSRaq
} fP:]s@$
} mKjTJzS
O&MH5^I
qdLzB
//打印回应的头信息 /O<~n%< G
public void logResponseHead(HttpURLConnection con) >yr;Y4y7K
{ :2H]DDg(
for(int i=1;;i++) K\wu9z8M
{ T;5VNRgpI
String header=con.getHeaderFieldKey(i); rrR"2WuGO
if(header!=null) )u+O~Y95&i
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k,$/l1D
Utility.log(header+" : "+con.getHeaderField(header)); |fywqQFq
else bfpeK>T
break; 3b\s;!
} ]?)uYot
} c&1_lI,tH
(V&8 WN
A1F$//a
public void splitterStop() Dt<MEpbur
{ $K+|bb
bStop = true; { TI,|'>5[
} L){V(*K '
c]Gs{V]\
2z*}fkJ
} Z'`\N@c#
<p CD>
p6NPWaBR
/* unc6 V%
**FileAccess.java !?_CIt$p
*//文件访问(定位，写) akk*f+TD`
package NetFox; FAL#p$y}
import java.io.*; 2*^=)5Gj-h
|JR`" nF`
bl&9O
public class FileAccessI implements Serializable{ T u%XhXl:j
l?$X.CwX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6eUGE4NF(
RandomAccessFile oSavedFile; M*bsA/Z
long nPos; Y[vP]7-
2+I5VPf
[u;(4sa}
public FileAccessI() throws IOException H>D sAHS
{ Y@:l!4DI
this("",0); _f8H%Kgk;
} "=n%L +6%
50dN~(;p
)b (+=
public FileAccessI(String sName,long nPos) throws IOException \BH?GMoP
{ Xp|4WM
oSavedFile = new RandomAccessFile(sName,"rw"); ob8}v*s
this.nPos = nPos; r>! @Z2%s
oSavedFile.seek(nPos); 9(qoME}>=
} ftcLP
q+4dHS)x
5x|$q kI
public synchronized int write(byte[] b,int nStart,int nLen) AA)pV-
{ Q=d:Yz":S
int n = -1; eaNfCXHDN
try{ wEl7mg !
oSavedFile.write(b,nStart,nLen); k>Fw2!mA^
n = nLen; *z6A ~U
} ern\QAhXX
catch(IOException e) sVFX(yx0
{ Xs|d#WbX
e.printStackTrace (); L~e0^X?
} 9{U@s
*g %bdO
M@7U]X$g
return n; !~RK2d
} wLiPkW
_.R]K$U
O-ENFA~E;v
} KPDJ$,:
]@cI_n
r_+!3
/* uH?4d!G
**SiteInfoBean.java N.+A-[7,W
*/ x^_c4,i)
package NetFox; 9>0OpgvC(
nu:l;+,VY
cUP1Uolvn
public class SiteInfoBean { h5T~dGRlR
Yc?S<
j~S=kYrGM
private String sSiteURL; //Site's URL !-n*]C
private String sFilePath; //Saved File's Path : O@(Sv
private String sFileName; //Saved File's Name 1c@S[y
private int nSplitter; //Count of Splited Downloading File h4itXJy52B
8%?MRRK
7)1%Z{Dy
public SiteInfoBean() ]b>XN8y.
{//nSplitter的缺省值为5 g18zo~LZ
//default value of nSplitter is 5 !gV{[j?~zr
this("","","",5); :-U&_%#w
} =bP<cC=3b
Y@q9
oiR9NB&<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (pM&eow}
{ ^fsC]9NS
sSiteURL= sURL; _g9j_ x:=
sFilePath = sPath; -DJ,<f*$
sFileName = sName; z79oj\&[
this.nSplitter = nSpiltter; As5l36
OAFxf,b
ltU{P|7!E
} P.Cn[64a+@
6C"zBJcGc
yxT}hMa
public String getSSiteURL() RTbV!I
{ rx;;|eb,
return sSiteURL; AqQ5L>:Gq
} ^V9|uHOJoq
4_CL1g
=aQlT*n%3
public void setSSiteURL(String value) DWx;cP8[
{ gaNe\
sSiteURL = value; 8"NPj0
} {/N8[?zML
uit.r^8l
3?`TEw~'
public String getSFilePath() IY[qWs
{ @*L-lx
return sFilePath; i"Hc(lg
} 3G 5xIr6
(RrC<5"
D+ .vg?8
public void setSFilePath(String value) Z eY*5m
{ 1#;^Z3
sFilePath = value; =_3rc\0
} Eb6cL`#N
SYQP7oG9oQ
KRn[(yr`%
public String getSFileName() yKK9b
{ @].!}tz
return sFileName; xzfugW
} XV4aR3n{Q
}X=c|]6i^
Uc,..
public void setSFileName(String value) U|.r -$|5P
{ EBk-qd a}
sFileName = value; 'r_Fi5[q
} 7@e}rh?N-|
;o;ak.dTt
[euR<i*I#
public int getNSplitter() 9mn~57`y
{ 1 |)CQ
return nSplitter; l O*
} tQxxm=>
EB}~^ aY
&;r'JIp
public void setNSplitter(int nCount) ^ T`T?*h
{ *qLk'<
nSplitter = nCount; mea} 9]c
} @x A^F%(
} @ZJ}lED3
|=~mRqG
lfd-!(tXD
/* v$JW7CKA
**Utility.java #h9Gl@|
*/ t;PG
package NetFox; q(R|3l^6T
w@6y.v1I{
*}Gys/\!S
public class Utility { rK}sQ4z=
1=9GV+`n
}hm_Ws
public Utility() 5 b,|6
{ ypemp=+(r
-`z%<)!Y
n_Y7*3/b-o
} 0Krh35R_)F
qkp0'f*}
//线程睡眠 $T66%wX
public static void sleep(int nSecond) o /1+ }f
{ 0Y0`$
try{ nra)t|m
Thread.sleep(nSecond); -k2|`t _
} ?|}qT05
catch(Exception e) d( ru5*p
{ ;l0%yg/}
e.printStackTrace (); T$<'ZC
} :f_oN3F p
} BNb_i H
;.=0""-IF
//日志 jA~omX2A
public static void log(String sMsg) SdMLO6-
{ >\J<`
System.err.println(sMsg); 1P'L<z
} '^7UcgugB
'"LaaTTs
hcYqiM@8>
public static void log(int sMsg) d1t_o2
{ xb9^WvV
System.err.println(sMsg); 4f~q$Sf]<
} lg ,%
} Y$)y:.2#
aM#xy6:XG
MYz!zI
/* eAjR(\f>
**TestMethod.java 63$`KG3
*/ 0jxXUWO
package NetFox; 55] MRv
u WdKG({][
cG@Wo8+
public class TestMethod { Qz2jV
jeA2yjAC
C{G=Y[?oc
public TestMethod() -{z[.v.p
{ ///xx/weblogic60b2_win.exe =JPY{'VO
try{ 0@EI@X;q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SJ;{ Hg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); P%vouC0W
SiteFileFetch fileFetch = new SiteFileFetch(bean); 2S[:mnK
fileFetch.start(); @7Ln1v
} >Lo'H}[pF
catch(Exception e){e.printStackTrace ();} M)wNu
Rp:I&f$Hk/
)Wt&*WMFXl
} 9U3}_
E(1G!uu<
CQ Ei(ty
public static void main(String[] args) 10r!p:D
{ **AkpV)
new TestMethod(); yOXEP
} 4&e<Sc64
} maQxU(
点击下载更多相关资料