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)); oN2#Jh%dH
} xkCM*5:
for(int i=0;i<nEndPos.length-1;i++) /!?b&N/d)
{ EHy15RL
nEndPos = nStartPos[i+1]; \o*w#e[M
} qjObu\r
nEndPos[nEndPos.length-1] = nFileLength; ~R&rQJJeJ
} qj9[mBkP"
} JC0#pU;
{]bmecz
S B~opN
//启动子线程 -Uan.#~S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5@DCo
for(int i=0;i<nStartPos.length;i++) Mw3$QRM
{ E{0e5.{
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), in K]+H]{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), +BeA4d8b
nStartPos,nEndPos,i); DIABR%0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &gJ1*"$9
fileSplitterFetch.start(); D6~KLSKm
} Wv|CJN;4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |a#=o}R_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P3.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o}DRp4;Ka
nEndPos = " + nFileLength); -AD@wn!wCJ
// fileSplitterFetch[nPos.length-1].start(); uwQgu!|x
_TLspqi
Nw9@E R
//等待子线程结束 E[WU
//int count = 0; 7]} I
//是否结束while循环 R?zlZS.~
boolean breakWhile = false; idB1%?<
oi m7=I0
-:95ypi
while(!bStop) \q?^DI:`
{ el U%Z9
write_nPos(); w$IUm_~waa
Utility.sleep(500); 4#{f8
breakWhile = true; [n2zdiiBd
Qo:vAv
,,H;2xYf
for(int i=0;i<nStartPos.length;i++) F!3p )?
{ O1UArD
if(!fileSplitterFetch.bDownOver) R%4Yg(-Q
{ @<3E`j'p
breakWhile = false; Q7<Y5+
break; oi]XSh[_s
} gzlxkv-F{
} O&MH5^I
if(breakWhile) ;O1jf4y
break; /O<~n%< G
9 Jw,ls
>yr;Y4y7K
//count++; :2H]DDg(
//if(count>4) K\wu9z8M
// siteStop(); +.&P$`;TZj
} ?%`Ph ?BZl
V@]SKbK}wN
Y(t/=3c[
System.err.println("文件下载结束！"); }]H7uC!t
} -. o,bg
catch(Exception e){e.printStackTrace ();} Rz&`L8Bz
} ia3Q1 9r
:1Nc6G
%3*|Su%uC
//获得文件长度 \?oT.z5VG&
public long getFileSize() 0J^Z)U>j
{ H#7=s{u
int nFileLength = -1; *Lxt{z`9
try{ c0Bqm
URL url = new URL(siteInfoBean.getSSiteURL()); W**[:n+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *+zFsu4l
httpConnection.setRequestProperty("User-Agent","NetFox"); =dH=3iCG
SHs [te[
GZWqPM4S\
int responseCode=httpConnection.getResponseCode(); epKr6 xq
if(responseCode>=400) U#[T!E
{ +pq) 7
processErrorCode(responseCode); z6}p4
return -2; //-2 represent access is error p7 !y#
} dH.Fb/7f
G62;p#
bl&9O
String sHeader; hxj\
45n.%*,
)5n0P Zi
for(int i=1;;i++) \9@}0}%`
{ }cI-]|)|2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ?mM:oQH+>
//Utility.log(in.readLine()); X31%T"
sHeader=httpConnection.getHeaderFieldKey(i); R<gAxO%8
if(sHeader!=null) sxA]o|
{ RhKDQGdd
if(sHeader.equals("Content-Length")) cuH5f}oc
{ ppRA%mhZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5Pq6X
break; 9od c :
} tK[o"?2y
} lwfM>%%N
else PYC
break; )Nx*T9!Q
} WY QVe_<z:
} QnOs8%HS-
catch(IOException e){e.printStackTrace ();} ZQym8iV/
catch(Exception e){e.printStackTrace ();} (tq);m&
7XT(n v
IJKdVb~
Utility.log(nFileLength); c~/poFj
n$NM
S"@6,
return nFileLength; 5FuV=Yuc
} A(uo%QE|
B_iaty
4"Qb^y
//保存下载信息（文件指针位置） Xs|d#WbX
private void write_nPos() L~e0^X?
{ 9{U@s
try{ *g %bdO
output = new DataOutputStream(new FileOutputStream(tmpFile)); @`+\vmfD
output.writeInt(nStartPos.length); 'v^shGI%Ht
for(int i=0;i<nStartPos.length;i++) shL_{}
{ [qV/&t|O*h
// output.writeLong(nPos); M:(.aEe
output.writeLong(fileSplitterFetch.nStartPos); aCH;l~+U
output.writeLong(fileSplitterFetch.nEndPos); c$)>$&([
} `n-/~7
output.close(); ?7TmAll<.s
} cAGM|%
catch(IOException e){e.printStackTrace ();} }f_@@#KB?
catch(Exception e){e.printStackTrace ();} RhmkpboucC
} J @~g>
Ct?xTFb
uPbdzUk$
//读取保存的下载信息（文件指针位置） Y@k=m )zE
private void read_nPos() 3N!v"2!#
{ Vt \g9-[
try{ =jh^mD&'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9{geU9&Z
int nCount = input.readInt(); nh0gT>a>@
nStartPos = new long[nCount]; <+r~?X_
nEndPos = new long[nCount]; p5OoDo
for(int i=0;i<nStartPos.length;i++) qc.TYp
{ !5h-$;
nStartPos = input.readLong(); 'AWWdz
nEndPos = input.readLong(); zt9A-% \R
} 9=6BQ`u
input.close(); Nxl#]
} g~,iWoY
catch(IOException e){e.printStackTrace ();} =bP<cC=3b
catch(Exception e){e.printStackTrace ();} ,SIGfd
} oiR9NB&<
(pM&eow}
^fsC]9NS
private void processErrorCode(int nErrorCode) _g9j_ x:=
{ -DJ,<f*$
System.err.println("Error Code : " + nErrorCode); z79oj\&[
} As5l36
/&G|.Cx
ltU{P|7!E
//停止文件下载 +:jv )4^O
public void siteStop() 6Y6t.j0vN.
{ w;(=wN\
bStop = true; q&3(yhx
for(int i=0;i<nStartPos.length;i++) /qwY/^
fileSplitterFetch.splitterStop(); !mWm@}Ujg
~iiDy;"
;5$ GJu(
} nL[OwfPj
} vg3iT}
//负责部分文件的抓取 {/N8[?zML
**FileSplitterFetch.java ge%QbU1J
*/ 3?`TEw~'
package NetFox; IY[qWs
@*L-lx
G(shZ=fq
import java.io.*; 3G 5xIr6
import java.net.*; (RrC<5"
o(> #}[N}
Z eY*5m
public class FileSplitterFetch extends Thread { Ktt(l-e+
)+Z.J]$O-
J4j:nd
String sURL; //File URL z19%!k
long nStartPos; //File Snippet Start Position C|g1:#0
long nEndPos; //File Snippet End Position ]oz>/\!
int nThreadID; //Thread's ID 0|K<$e6IH
boolean bDownOver = false; //Downing is over fuCt9Kjo<
boolean bStop = false; //Stop identical !a\HdQ
FileAccessI fileAccessI = null; //File Access interface 3}3b@:<
;gu4~LQw
Sfc,F8$&N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H/Ql
{ )K::WqR%w)
this.sURL = sURL; O[L#|_BnEO
this.nStartPos = nStart; X7-[#} T
this.nEndPos = nEnd; B]b/(Q+
nThreadID = id; z<^LY]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }M"])B I
} "Dq^r9
=+?OsH v
[4bE"u
public void run() W?!rqo2SP
{ ,CPAS}kS
while(nStartPos < nEndPos && !bStop) ez%:>r4
{ 9M1DE
~Al3Dv9x
.q:6F*,1M
try{ :yi} CM4
URL url = new URL(sURL); Q3$DX,8?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); JV4fL~
httpConnection.setRequestProperty("User-Agent","NetFox"); #h9Gl@|
String sProperty = "bytes="+nStartPos+"-"; t;PG
httpConnection.setRequestProperty("RANGE",sProperty); q(R|3l^6T
Utility.log(sProperty); w@6y.v1I{
eTw9c }[
.!lLj1?p
InputStream input = httpConnection.getInputStream(); ,!,M'<?"
//logResponseHead(httpConnection); 73]t5=D:
o$U{.#
S1~K.<B
byte[] b = new byte[1024]; m J$[X
int nRead; z%JN|5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y] O&w{m$
{ Fo%`X[?
nStartPos += fileAccessI.write(b,0,nRead); e0ni
//if(nThreadID == 1) zLg$|@E&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XDyo=A]
} gcO$T`
& @_PY
nUX3a'R
Utility.log("Thread " + nThreadID + " is over!"); <4@8T7
bDownOver = true; m#O; 1/P
//nPos = fileAccessI.write (b,0,nRead); (]&B'1b
} 9H:J&'Xi7
catch(Exception e){e.printStackTrace ();} Zy?!;`c*{
} GNB'.tJ:0Y
} :9x]5;ma
*uccY_
2~ETu&R:
//打印回应的头信息 7PUy`H,&
public void logResponseHead(HttpURLConnection con) @8aV*zjB
{ 7i02M~*uS
for(int i=1;;i++) 08k
{ ` l'QAIo
String header=con.getHeaderFieldKey(i); *A}td8(
if(header!=null) U,fPG/9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vflC{,{=k>
Utility.log(header+" : "+con.getHeaderField(header)); >zw@!1{1
else hPGDN\#LD
break; "s_S!;w@
} <HS{A$]
} =`N0
U#w0E G
*u,xBC2C
public void splitterStop() k,<7)-
{ /P46k4M1U
bStop = true; KIWHn_ :
} MU `!sb*
0Ny +NE:6M
d|~'#:y@
} @;{ZnRv14
x{So
'0_W<lGB
/* $rbr&TJ
**FileAccess.java T?jN/}qg
*//文件访问(定位，写) tO1k2<Z"Y&
package NetFox; 4 CiRh
import java.io.*; Hv:~)h$
^u0y<kItX
@<4U &
public class FileAccessI implements Serializable{ l>BM}hS
CQ Ei(ty
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 v/$<#2|
RandomAccessFile oSavedFile; U%#Vz-r
long nPos; 4&e<Sc64
j':<7n/A
Pd `~#!
public FileAccessI() throws IOException xH,e$t#@@~
{ ^HTvw~]5
this("",0); |m*l/@1
} >lek@euqw
I)r6*|mz
e85E+S%
public FileAccessI(String sName,long nPos) throws IOException H ]](xYy.
{ 9q&~!>lt
oSavedFile = new RandomAccessFile(sName,"rw"); gF293Ez
this.nPos = nPos; q%]5/.J
oSavedFile.seek(nPos); e~,+rM
} V!TGFo}
opzlh@R 3
_o+OkvhU
public synchronized int write(byte[] b,int nStart,int nLen) 8)Vl2z
{ qAlX#]
int n = -1; 3Y +;8ld
try{ -sDl[
oSavedFile.write(b,nStart,nLen); 6-5{7E}/b
n = nLen; &H}Xk!q5b^
} y0) mBCX
catch(IOException e) [L|vBr
{ Klu0m~X@
e.printStackTrace (); I?\P^f
} sdd%u~4,X
z`u$C+Ov
&=T>($3r94
return n; :qShP3^
} =t~]@?]1D
v=&xiwz}
mOyNl -f
} Ar_Yl|a
W%9~'pXgB
h*Mi/\
/* q8R,#\T*
**SiteInfoBean.java 'fzJw
*/ zpNt[F?~1
package NetFox; ]'>jw#|h
Go]y{9+(7
{aopGu?i
public class SiteInfoBean { 6vU%Y_n=y]
\t&8J+%
ir|L@Jj,
private String sSiteURL; //Site's URL F<*zL:-Z
private String sFilePath; //Saved File's Path {8%KO1xB
private String sFileName; //Saved File's Name HuN_$aP
private int nSplitter; //Count of Splited Downloading File 4>B=k
(Bpn9}F-V.
DD>n-8M@>
public SiteInfoBean() .H&XPW
{//nSplitter的缺省值为5 sYk#XNH
//default value of nSplitter is 5 !9V; 8g
this("","","",5); VPVg\K{
} 7kMO);pO
NKVLd_f k
X@A8~kj1
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0juP"v$C>
{ QV#HN"F/K
sSiteURL= sURL; uFvR(LDb&g
sFilePath = sPath; .i#'IS0c
sFileName = sName; AJ#YjkO>]
this.nSplitter = nSpiltter; 01]W@\(
D7jbo[GgS
YCdtf7P=q
} Y|KT3
Cw5B p9
*d 4A3|
public String getSSiteURL() N6*FlG-
{ 1k$5'^]^9]
return sSiteURL; g<8Oezi 65
} 2';{o=TXV
>I+p;V$@
]x'd0GH"]
public void setSSiteURL(String value) Jr(Z Ym'
{ @v\8+0
sSiteURL = value; _ZK*p+u%
} I%z,s{9p
a`U/|[JM
_@_EQ!=
public String getSFilePath() *A0d0M]cg
{ R|*Eg,1g -
return sFilePath; IfP?+yPa
} G//hZwf0
ow'CwOj$
%w/vKB"nO
public void setSFilePath(String value) m1sV~"v;
{ u})8)
sFilePath = value; sM9utR
} !_iv~Q zv
xd4~[n\hm
=W gzj|Kr
public String getSFileName() 0R-W9qP
{ )]zsAw`/
return sFileName; M~.1:%khM
} W*u$e8i7
Y44[2 :m
jZe/h#J)[
public void setSFileName(String value) A5s;<d0
{ -x!JTx[K
sFileName = value; m`tX&K#-
} 2=VFUR 8
q{L-(!uz7_
xd+aO=)Td
public int getNSplitter() u!FF{~5cs
{ 60xL.Z
return nSplitter; !2.eJ)G
} -^< t%{d
DX/oHkLD'
JL7;l0#
public void setNSplitter(int nCount) Y/L*0M.<
{ wxF\enDY
nSplitter = nCount; \[AJWyP
} +u`4@~D#
} nIfp0U*
Jpn= ^f[rm
{WTy/$ Qk
/* xg'xuz$U
**Utility.java l4& l)4Rx
*/ .OlPVMFt
package NetFox; R I:kp.V
}LoMS<O-[
34J*<B[Njo
public class Utility { 0~Xt_rN](
5>VX]nE3!
Z4sS;k]}
public Utility() MIqH%W.ru
{ "EZpTy}Ee
BxaGBK<k
4K|O?MUNS
} \GZ|fmYn
$3cZS
//线程睡眠 8zho\'
public static void sleep(int nSecond) mp*?GeV?M
{ O;0VKNn['
try{ jcRe),
Thread.sleep(nSecond); @qB>qD~WsD
} $s"-r9@q
catch(Exception e) w,OPM}) il
{ PlwM3lrj
e.printStackTrace (); R%`fd *g
} /RWD\u<l
} SErh"~[
~G.MaSm
//日志 [i_evsUj?
public static void log(String sMsg) v]T?xo~@'
{ ^E".`~R
System.err.println(sMsg); rkz84wDx
} vTC{
~m[Gp;pL
1yFIIj:^|
public static void log(int sMsg) t~":'le`zr
{ 8=g~+<A
System.err.println(sMsg); p ^9o*k`u
} ZWKvz3Wt
} (&X/n=UI
KWM}VZY:Z
7R,;/3wWjG
/* Uz%ynH
**TestMethod.java Zu94dFP
*/ i9T<(sdK+
package NetFox; ST,+]p3L(
z|zEsDh;
Q(4~r+
public class TestMethod { %\~U>3Q
. "7-f]!
G9@5 !-
public TestMethod() ^~dC&!D
{ ///xx/weblogic60b2_win.exe 3Z7gPU!H=
try{ d ]jF0Wx*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -vc ,O77z"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }nSu7)3$B
SiteFileFetch fileFetch = new SiteFileFetch(bean); uG-S$n"7K
fileFetch.start(); CY$ 1;/
} KDj/S-S
catch(Exception e){e.printStackTrace ();} 86a,J3C[
hDc2T
7\gu; [n
} o'8%5M@
}rF4M1+B\
TV`sqKW
public static void main(String[] args) G"".;}AV
{ j3u!lZ}U
new TestMethod(); *w/N>:V0p
} 3_]QtP3
} qx*N-,M%k(
点击下载更多相关资料