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)); gCv"9j<j
} Dk)@>l:gI,
for(int i=0;i<nEndPos.length-1;i++) `fQM
{ `t{D7I7
nEndPos = nStartPos[i+1]; {E!$ xY8
} _:wZmZU}
nEndPos[nEndPos.length-1] = nFileLength; p>k]C:h
} lZ}izl
} LQh^; ]^(
VDB$"T9#
a`7%A H)
//启动子线程 OOCQsoN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E^b pckP
for(int i=0;i<nStartPos.length;i++) Dz[566UD
{ yB-.sGu
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n=f`AmF;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), iKg75%;t
nStartPos,nEndPos,i); "#*Nnt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EKcC+g
fileSplitterFetch.start(); % 2I
} "Jb3&qdU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jmkRP"ZnA
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e Wc_N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y7CWBTH0>
nEndPos = " + nFileLength); 5B}3GBA
// fileSplitterFetch[nPos.length-1].start(); (FM4 ^#6
@q,)fBZq
Q2*/`L}m\
//等待子线程结束 N1PECLS?
//int count = 0; O x{Q.l
//是否结束while循环 |kId8WtA
boolean breakWhile = false; q#;BhPc
m'd^?Qc
;xL67e%?
while(!bStop) h]qT1(I
{ F vj{@B!
write_nPos(); +Qt[1Xq
Utility.sleep(500); !d\t:0;
breakWhile = true; ,,S9$@R
K6E}";;
!]yQ1@)*'
for(int i=0;i<nStartPos.length;i++) rqF"QU=l
{ G]b8]3^
if(!fileSplitterFetch.bDownOver) mj)PLZ]
{ i#k-)N _$
breakWhile = false; H\ 3M
break; _HwpPRVP/
} ]22C)<
} qc3~cH.@
if(breakWhile) ])C>\@c6Gm
break; >b'w'"
qB+n6y%
&(g|="T
//count++; PJCnud F
//if(count>4) G=1m]>I8
// siteStop(); -)X{n?i
} w5,6$#
RYt6=R+f
rw&y,%2
System.err.println("文件下载结束！"); }f0u5:;Zth
} JfkTw~'R
catch(Exception e){e.printStackTrace ();} q'.;W@m
} (]OFS;%
f7Zf}1|
"MTWjW*6
//获得文件长度 z4g+2f7h-X
public long getFileSize() eO'xkm
{ Ee8--
int nFileLength = -1; }S,-uggz
try{ #'C/Gya
URL url = new URL(siteInfoBean.getSSiteURL()); ~^x-ym5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )U'yUUi
httpConnection.setRequestProperty("User-Agent","NetFox"); IdF$Ml#[h
4Hk6b09
C,.-Q"juH
int responseCode=httpConnection.getResponseCode(); HM):"
if(responseCode>=400) y<|)'(
{ h`lmC]X_
processErrorCode(responseCode); lcCJ?!lsSW
return -2; //-2 represent access is error 6%%PP8.F
} 2% %|fU9
[@<G+j
u%xDsTDP
String sHeader; U%q:^S%#eG
WV2~(/hX&
v{.\iIg N
for(int i=1;;i++) O] H=s
{ _#FIay\ahB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); c# xO<
//Utility.log(in.readLine()); {|XQO'Wg
sHeader=httpConnection.getHeaderFieldKey(i); a!D*)z Y
if(sHeader!=null) GQ<Ds{exs>
{ Y#`Lcg+r,
if(sHeader.equals("Content-Length")) awFhz 6
{ 9k}<Fz"^.
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); O^0"
break; l DnMjK\M
} Z:|9N/>T
} VJg,~lQN#t
else 7G"7wYc>R
break; ,%Z&*n
} AFm,CINa
} XIRR Al(,
catch(IOException e){e.printStackTrace ();} H*rx{F?
catch(Exception e){e.printStackTrace ();} pqeL%="p;
.gq(C9<B[
<5I1DF[
Utility.log(nFileLength); 5qRc4d'
r4?b0&Xq
]26mB
return nFileLength; JpmB;aL#%
} ]n5"Z,K
-;>#3O-
/l6\^Xf{
//保存下载信息（文件指针位置） Yx),6C3
private void write_nPos() ?q!FG(
{ ~.6|dw\p!
try{ Y\p$SN
output = new DataOutputStream(new FileOutputStream(tmpFile)); FsY(02
output.writeInt(nStartPos.length); qg4fR' i
for(int i=0;i<nStartPos.length;i++) 72,"Cj
{ +T2HE\
// output.writeLong(nPos); Qci$YTwl>
output.writeLong(fileSplitterFetch.nStartPos); 13a(FG
output.writeLong(fileSplitterFetch.nEndPos); Gs_qO)~xo
} 'gDe3@ci!
output.close(); l E^*t`+
} 5V@&o`!=h
catch(IOException e){e.printStackTrace ();} e\9g->DUs
catch(Exception e){e.printStackTrace ();} _!!}'fMC
} VNj@5s
]'k[u
7~b!4x|Z
//读取保存的下载信息（文件指针位置） !)c=1EX]"
private void read_nPos() ],[)uTZc
{ -CD\+d "
try{ +j[`,5oS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :Q-oV8t{
int nCount = input.readInt(); d0 -~|`5
nStartPos = new long[nCount]; @]=f?+y[ 2
nEndPos = new long[nCount]; HE;V zR
for(int i=0;i<nStartPos.length;i++) ZXt?[Ll
{ C),7- ?
nStartPos = input.readLong(); a4&:@`=
nEndPos = input.readLong(); nm@']
} %!y89x=E
input.close(); `c(\i$1JY)
} 8Z#21X>
catch(IOException e){e.printStackTrace ();} AIh*1>2Xn
catch(Exception e){e.printStackTrace ();} qS.)UaA
} TnA?u (R%
xo Gb
}1U*A#aN7K
private void processErrorCode(int nErrorCode) `f)(Y1%.
{ ,w2WS\`%
System.err.println("Error Code : " + nErrorCode); b/<mRQ{
} [AR>?6G-
a2yE:16o6
.X `C^z]+
//停止文件下载 xU}M;4kH~
public void siteStop() PLdn#S}.
{ l>&sIX
bStop = true; MEq"}zrh
for(int i=0;i<nStartPos.length;i++) yC !/PQ"
fileSplitterFetch.splitterStop(); {DBIonY];
|0 !I5|<k
<o0~H
} 9y^/GwUQ
} Sj-[%D*
//负责部分文件的抓取 IU!Ht>
**FileSplitterFetch.java kus}WJ
*/ ;6m;M63z
package NetFox; .Yx_:h=u
ZL_[4Y
6y Wc1
import java.io.*; (oaYF+T
import java.net.*; ]sj0~DI*m
aB"xqh)a}T
Rj6|Y"gq9
public class FileSplitterFetch extends Thread { HZZDv+
nl n OwyMJ
#w>~u2W
String sURL; //File URL 7[KCWJ
long nStartPos; //File Snippet Start Position CWlW/>yF B
long nEndPos; //File Snippet End Position o\6iq
int nThreadID; //Thread's ID L"vj0@n'0
boolean bDownOver = false; //Downing is over SW9fE:v
boolean bStop = false; //Stop identical P`"mM?u
FileAccessI fileAccessI = null; //File Access interface (V?@?25
u) *Kws
WRpyr
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException eVt1d2.O
{ ?CY1]d
this.sURL = sURL; x(~<tX~
this.nStartPos = nStart; HI!4
this.nEndPos = nEnd; OW`STp!
nThreadID = id; Gv~p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 T PYDs+U
} M"wue*&
Q~Ea8UT.#
nvyB/
public void run() 8;n_TMb
{ 6E^~n
while(nStartPos < nEndPos && !bStop) `w<J25
{ QUOKThY?
sN/+
l[%lE
try{ (E!!pz
URL url = new URL(sURL); Z'M`}3O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5DFZ^~
httpConnection.setRequestProperty("User-Agent","NetFox"); #Ufo)\x
String sProperty = "bytes="+nStartPos+"-"; 213\ehhG<
httpConnection.setRequestProperty("RANGE",sProperty); >Ko[Xb-8^_
Utility.log(sProperty); \=nrt?
36$[
o""~jc~
InputStream input = httpConnection.getInputStream(); KCtX$XGL
//logResponseHead(httpConnection); &;>4N"]
BSzkW}3q9
qO()w
byte[] b = new byte[1024]; {-WTV"L5*2
int nRead; lhPGE_\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C1fyV]
{ v?j!&d>
nStartPos += fileAccessI.write(b,0,nRead); Kf.T\V4%
//if(nThreadID == 1) P))^vUt~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MCYl{uH!
} JwP:2-o
(vyz;Ob
oNYZIk:
Utility.log("Thread " + nThreadID + " is over!"); (?Q|s,
bDownOver = true; `s/?b|,
//nPos = fileAccessI.write (b,0,nRead); YQVcECj
} K=\&+at1
catch(Exception e){e.printStackTrace ();} Ijedo/
} }[n5n
} IZNOWX|Z;
>D_F!_
&drFQ|
//打印回应的头信息 LWmB, Zf/
public void logResponseHead(HttpURLConnection con) KoHGweKl#
{ F ?=9eISLJ
for(int i=1;;i++) !%S4n
{ }ugxN0
String header=con.getHeaderFieldKey(i); d2jr8U
if(header!=null) #`ejU&!6
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :zp`6l
Utility.log(header+" : "+con.getHeaderField(header)); "H+,E_&(
else ijW7c+yd
break; ' 4O-
} PK:2xN:=
} w^;DG
o`?zF+M0
>K)2NLW\xA
public void splitterStop() I=rwsL
{ Iti0qnBN5
bStop = true; 7"Mk+'
} >^SEWZ_[
9&
#oV+@D`
} p'Bm8=AwD
~W{-Q.
Q5n`F5
/* bToq$%sCg
**FileAccess.java wCb(>pL0
*//文件访问(定位，写) f[jNwb
package NetFox; 4Z5#F]OA7
import java.io.*; HEY4$Lf(I
|>1hu1
z2 hFn&
public class FileAccessI implements Serializable{ aC^$*qN-)
~5OL6Bi-q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ai-n z-;
RandomAccessFile oSavedFile; -5Utlos
long nPos; |b.z*G
PCE4W^ns
tP(h9|[N
public FileAccessI() throws IOException P:{<*`q
{ Qvqqvk_tv
this("",0); ls|LCQPx
} 82:Wvp6
x` /)g(
:tj-gDa\Y
public FileAccessI(String sName,long nPos) throws IOException SbT5u3,'
{ ;Yts\4BSM
oSavedFile = new RandomAccessFile(sName,"rw"); Vfs$VY2.
this.nPos = nPos; !:0v{ZQ
oSavedFile.seek(nPos); ^[q /Mw
} Xs$Ufi
j8$Zv%Ca%
r`M6!}oa
public synchronized int write(byte[] b,int nStart,int nLen) r4{<Z3*N
{ |g&ymFc
int n = -1; [EZYsOr.
try{ %&+59vq
oSavedFile.write(b,nStart,nLen); HuI`#.MpWE
n = nLen; \8v91g91f
} *l+Cl%e
catch(IOException e) wpo1
{ ^k/i-%k0
e.printStackTrace (); Op}ZB:
} ^DAu5|--R
0D~ Tga)
|m*.LTO
return n; Ciihsm
} bbN%$/d
;_"U "?h_J
+c$I&JO
} #@f[bP}a
wWjG JvJ
m7jA ,~O
/* ukAKFc^)k
**SiteInfoBean.java @wN G
*/ o(G"k
package NetFox; xvm5
h5~n 1qX
]k%PG-9
public class SiteInfoBean { dl|gG9u4Q
P~ 0Jg# V
:#{Xuy:
private String sSiteURL; //Site's URL `!4,jd
private String sFilePath; //Saved File's Path FfFak@H
private String sFileName; //Saved File's Name +l0g`:
private int nSplitter; //Count of Splited Downloading File 93Yn`Av;
SaDA`JmO
"lVqU
public SiteInfoBean() l|"6yB |
{//nSplitter的缺省值为5 [M+tB"_
//default value of nSplitter is 5 ,T5u'";
this("","","",5); I0Ia6w9
} _eQ-`?
>hsuAU.UOR
[~mGsXV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =JO^XwUOo
{ Paf%rv2
sSiteURL= sURL; +]wuJSxc
sFilePath = sPath; q9*MNHg}
sFileName = sName; <M+R\SH-
this.nSplitter = nSpiltter; CboLH0Fa
!!,0'c
OSDy'@
} grom\
:1wrVU-?h
;y>a nE}n{
public String getSSiteURL() ql{_%x?
{ L8$1K&!
return sSiteURL; Ib`-pRU;
} #bnb': f
b{Zpux+
b$JBL_U5Ch
public void setSSiteURL(String value) #5ax^p2*~
{ On_@HQ/FI
sSiteURL = value; B(5c9DI`
} ]N)DS+V/
ERMa# L
kuMKX`_
public String getSFilePath() 1Y/$,Oa5
{ \Sy7"a
return sFilePath; 0D&>Gyc*0
} fw-\|fP
^))RM_ic
p<GR SJIk=
public void setSFilePath(String value) !PUZWO
{ OM83S|1s
sFilePath = value; Fd$!wBL
} !u|Tu4G^
MmoR~~*
t%VDRZo7
public String getSFileName() ]`o!1(GA
{ GHc/Zc"iX
return sFileName; ?A*Kg;IU
} Fwg^(;bL
t'qL[r%?
q0xjA
public void setSFileName(String value) jA(vTR.`
{ X]j)+DX>
sFileName = value; hvV_xD8|
} c-1q2y
Xq#Y*lKVD
|L3X_Me
public int getNSplitter() xhs#u
{ #KpY6M-H
return nSplitter; eny/ fm
} Ve3 ;
n(ir[w#,]"
EMvHFu
public void setNSplitter(int nCount) ,XKCz ]8V
{ sH#X0fG
nSplitter = nCount; _=f=fcl
} epD?K
} @tUoD>f
#Z,E><t
':h =*v8a
/* Rd&9E
**Utility.java kyYLP"oB=
*/ +g*k*e>l
package NetFox; ;@mRo`D`
Sr Ca3PA
_'0 @%P%
public class Utility { X"asfA[6K
},-*
Tenf:Hm/k
public Utility() q3e8#R)l
{ ^z;JVrW
Jl<ns,Zg
lHfe<j]
} i\?*=\a
\1%l^dE@
//线程睡眠 vv0Q$ O->
public static void sleep(int nSecond) ,I.WX,OR
{ ?,knit2x
try{ e)^j+ l
Thread.sleep(nSecond); }%!tT\8
} F3U`ueP
catch(Exception e) a|j%n
{ 0S/' 94%w
e.printStackTrace (); fRZ KEIyk
} ^-)txC5{T
} GRqT-/n"
77 r(*.O|
//日志 vG.9H_&
public static void log(String sMsg) PA;6$vqX
{ {d3<W N
System.err.println(sMsg); vXj<
} Q+q,!w8
63WS7s"
L,[;k
public static void log(int sMsg) k\r(=cex6
{ ?knYY>Kzh1
System.err.println(sMsg); /*)Tl
} %D}H|*IPu
} =^DLywAh}u
_RkuBOv@e
f2I6!_C!+
/* myFAKRc
**TestMethod.java v}JD2.O+
*/ yzsab ^]
package NetFox; K{fsn4rk
&K+0xnUH
]88];?KS}
public class TestMethod { qPGuo5^
xJ8%<RR!t
kJ:F *34e=
public TestMethod() U/{6% Qy
{ ///xx/weblogic60b2_win.exe Zi\['2CG
try{ W-~n|PX8+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U977#MXf
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); >ezi3Zx^
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5II(mSg8
fileFetch.start(); Y k7-`
} tB7}|jC
catch(Exception e){e.printStackTrace ();} d(`AXyw
'])2k@o@
*LC+ PZV@
} uGN^!NG-0
XM1`x
qO1tj'U<
public static void main(String[] args) \00DqL(Oj`
{ eJCjJ)
new TestMethod(); 6vKS".4C
} o]n!(f<(*
} g| <wyt[
点击下载更多相关资料