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)); 4Iz~3fqB7
} E)`+1j
for(int i=0;i<nEndPos.length-1;i++) FuD$jsEw
{ kweypIB
nEndPos = nStartPos[i+1]; {RzlmDStV
} <$UY{"?
nEndPos[nEndPos.length-1] = nFileLength; O|8p #
} rc"Z$qU?
} U#Ud~Q q
t]Oxo`h=
nTLdknh"
//启动子线程 +VTMa9d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,fL*yn
for(int i=0;i<nStartPos.length;i++) i |C'_gw`n
{ @P%&Dha
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #t;@x_2yD\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KF-n_:Bd+
nStartPos,nEndPos,i); P[D^*}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pN?
fileSplitterFetch.start(); h'wI/Z_'
} "_9Dau$
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &u.t5m7(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]A'E61t<n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B[8
nEndPos = " + nFileLength); snX5mD
// fileSplitterFetch[nPos.length-1].start(); z0c_&@uj*
8)T.[AP
;Lz96R@}
//等待子线程结束 @c5TSHSL.
//int count = 0; LA1UD+S
//是否结束while循环 ^f@EDG8
boolean breakWhile = false; Lg-Sxz}P!
]81P<Y(7
'b%S3)}
while(!bStop) h\jwXMi,tj
{ d?'q(6&H
write_nPos(); XO219
Utility.sleep(500); YX-G>.Pc
breakWhile = true; 2b2/jzO}J
hbn2(e;FZ
IRD?.K]*
for(int i=0;i<nStartPos.length;i++) |LWG7 ZE
{ ]M#_o]
if(!fileSplitterFetch.bDownOver) `N$<]i]s5
{ gLU #\d]
breakWhile = false; 9z,V]v=
break; .%.J Q
} >/GVlXA'
} TTu<~GH
if(breakWhile) !@5B:n*
break; EE-jU<>|
]Z6==+mCP
E{|j
//count++; usX aT(K
//if(count>4) Y=\;$:L[
// siteStop(); jgbE@IA@!'
} cjp H hoW
n-0RA~5z
Q`'w)aV
System.err.println("文件下载结束！"); g"^<LX-
} 6Xbo:#
catch(Exception e){e.printStackTrace ();} ``DS?pUY
} 8Y_wS&eB
HvLvSy1U
Xb.WI\Eh
//获得文件长度 w7s+6,
public long getFileSize() xmsw'\
{ tWT@%(2~0
int nFileLength = -1; } U\n:@:2B
try{ (w`9*1NO
URL url = new URL(siteInfoBean.getSSiteURL()); cl/}PmYIZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G?v]p~6
httpConnection.setRequestProperty("User-Agent","NetFox"); >+LFu?y
R$sG*=a!8j
9/'zk
int responseCode=httpConnection.getResponseCode(); [AA'Ko
if(responseCode>=400) 7G zf>n
{ @FU9!
processErrorCode(responseCode); ha&2V=
return -2; //-2 represent access is error @Ge\odfF:
} ef*Vs
kzcl
Z]jm.'@z@
String sHeader; 5R"iF+p4
%L,mj
L/t'|<m
for(int i=1;;i++) iK%%
{ lpi^<LQ@l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jv_z%`
//Utility.log(in.readLine()); Rf9;jwU
sHeader=httpConnection.getHeaderFieldKey(i); m:_'r"o
if(sHeader!=null) K*NCIIDh
{ s"gNHp.oF
if(sHeader.equals("Content-Length")) gn4+$f~w
{ u?,M`w0'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); OTwIR<_B+
break; C3>&O?7J*7
} 9=YX9nP
} lXso@TNrZ0
else V $Y=JK@
break; <#HQU<
} rY yB"|
} Vz[tgb]-
catch(IOException e){e.printStackTrace ();} X+dLk(jI`u
catch(Exception e){e.printStackTrace ();} 1g<jr.
-!4Mmp"2@u
Jga;nrU
Utility.log(nFileLength); JB[n]|
uI lm!*0
F`))qCgg]
return nFileLength; F8Y_L\q
} +J[<zxh\
_[IOPHa"
/zV&ebN]
//保存下载信息（文件指针位置） ;=r_R!d@
private void write_nPos() {^(h*zxn
{ t`%Xxxu
try{ 3}hJ`xQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); oA+/F]XJ
output.writeInt(nStartPos.length); GP<PU
for(int i=0;i<nStartPos.length;i++) CvkZ<i){
{ b%A+k"d
// output.writeLong(nPos); $DS|jnpV
output.writeLong(fileSplitterFetch.nStartPos); meJ%mY
output.writeLong(fileSplitterFetch.nEndPos); Pnl+.?
} xs?Ska,N
output.close(); rlMahY"C
} aq,Ab~V]
catch(IOException e){e.printStackTrace ();} ~[a6
catch(Exception e){e.printStackTrace ();} v_G1YC7TU
} 1xBgb/+
GoSdo
f N_8HP6&
//读取保存的下载信息（文件指针位置） 9:9gam
private void read_nPos() 3:wN^!A}ve
{ C6` Tck!
try{ UmEc")3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); b;xn0sDn#
int nCount = input.readInt(); j3=%J5<
nStartPos = new long[nCount]; dBRK6hFC
nEndPos = new long[nCount]; Bl$Hg,in-
for(int i=0;i<nStartPos.length;i++) "($"T v2
{ -HQ(t
nStartPos = input.readLong(); hlKM4JT\
nEndPos = input.readLong(); @{V bu
} $@utlIXA'
input.close(); Te d1Ky2O
} xky +"
catch(IOException e){e.printStackTrace ();} Mj!g1Q
catch(Exception e){e.printStackTrace ();} "Sb<"$:
} a*2JLK
ka=EOiX.
9@3cz_[J
private void processErrorCode(int nErrorCode) to,\sc
{ 0^('hS&
System.err.println("Error Code : " + nErrorCode); omu)s '8
} xu<oQBt
\0fS;Q^{j
15J t @{<r
//停止文件下载 vCX 54
public void siteStop() 0]k-0#JM
{ 4"^v]&I
bStop = true; &9OnN<mT1
for(int i=0;i<nStartPos.length;i++) jCp^CNbA
fileSplitterFetch.splitterStop(); ;M<R e
3sD/4 ?
8{4SaT.-Rm
} IoKN.#;^
} _jWGwO
//负责部分文件的抓取 g>*P}r~;^b
**FileSplitterFetch.java :q34KP
*/ WJU[+|J
package NetFox; JavSR1_
N!lQ;o'
Wj INY
import java.io.*; s:zz8oN
import java.net.*; Q ym=L(X
$*$X5
Eg+z(m$M
public class FileSplitterFetch extends Thread { sI<PYi={-6
8[rZRc
^~`t q+
String sURL; //File URL CNM pyr
long nStartPos; //File Snippet Start Position =wquFA!c
long nEndPos; //File Snippet End Position Mwtd<7<!A
int nThreadID; //Thread's ID V:'_m'.-Y
boolean bDownOver = false; //Downing is over M$Or|HTG
boolean bStop = false; //Stop identical W&=F<n`
FileAccessI fileAccessI = null; //File Access interface _z6" C8W
irooFR[L9
,V &RpKek
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException v43FU3
{ (|dN6M-.K
this.sURL = sURL; HDQH7Bs
this.nStartPos = nStart; 8i~n;AhDs
this.nEndPos = nEnd; vYNu=vnM
nThreadID = id; |2!cPf^8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *\#?)q
} $:IEpV{
f#3!Q!C^
m{?uR.O
public void run() U2CCjAgRs
{ yL#2|t(
while(nStartPos < nEndPos && !bStop) qr'P0+|~5
{ v=J[p;H^H
eh /QFm 4
M/evZ?uis
try{ "JpnmE[`
URL url = new URL(sURL); 9jf2b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <sor;;T
httpConnection.setRequestProperty("User-Agent","NetFox"); snvixbN
String sProperty = "bytes="+nStartPos+"-"; |PutTcjQ
httpConnection.setRequestProperty("RANGE",sProperty); ><w=
Utility.log(sProperty); _ lE d8Cb
VRA0p[
aX}:O
InputStream input = httpConnection.getInputStream(); T{4Ru6[
//logResponseHead(httpConnection); ay>u``$R
,}23
XK,l9 {*
byte[] b = new byte[1024]; ;@s'JSPt
int nRead; nO;t5d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $E6bu4I
{ ?bw1zYP
nStartPos += fileAccessI.write(b,0,nRead); J_N`D+m
//if(nThreadID == 1) V1 O]L66
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U}:e-
} Bs;.oK5!n@
hZ~\Z S7
|.{[%OJP
Utility.log("Thread " + nThreadID + " is over!"); ~9JLqN"
bDownOver = true; HOb0\X
//nPos = fileAccessI.write (b,0,nRead); dU.H9\p
} v~KgCLo
catch(Exception e){e.printStackTrace ();} }gtkO&
} @f%q ,:
} @ $2xiE.[
aP`V
]#P>wW
//打印回应的头信息 Q|Go7MQZ@k
public void logResponseHead(HttpURLConnection con) <~iA{sY)O
{ 'w`3( ':=
for(int i=1;;i++) &k@r23V7r
{ |yYu!+U
String header=con.getHeaderFieldKey(i); 2>h.K/pC
if(header!=null) n+H);Dg<8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o}6d[G>
Utility.log(header+" : "+con.getHeaderField(header)); VhX~sJ1%Gp
else o\-:
break; :FWo,fq?:{
} Kn4x_9
} c~v(bK
F8OE
1zWEK]2.R
public void splitterStop() @ZtDjxN &
{ 7!jbID~
bStop = true; BjAmM*k
} M'}iIO`L
3}V-'!
cRS2v--\-
} B^lm'/,@
(C60HbL
zMbz_22*
/* U9%#(T$
**FileAccess.java D9-D%R,
*//文件访问(定位，写) D/TEx2.=J3
package NetFox; G;yh$n<"
import java.io.*; f) @-X!
xq\A TON
f,WAl\
public class FileAccessI implements Serializable{ 6R';[um?q
nEbJ,#>Z
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 (f>~+-IL
RandomAccessFile oSavedFile; qb?9i-(
long nPos; rBrJTF:.
h?+bW'm
9,>u,
public FileAccessI() throws IOException q<>aZ|r
{ h+d3JM
this("",0); A-5'OI
} * vW#XDx
V7q-Pfh!y
q}MPl2
public FileAccessI(String sName,long nPos) throws IOException ]}HuK#
{ mrId`<L5l{
oSavedFile = new RandomAccessFile(sName,"rw"); 6ujePi <U
this.nPos = nPos; *Rj(~Q/t
oSavedFile.seek(nPos); sJB::6+1(|
} >uVr;,=y
1Aw/-FxJ
#azD&6`
public synchronized int write(byte[] b,int nStart,int nLen) 2#t35fU
{ uwhb-.w
int n = -1; :Miri_l
try{ 9Netnzv%
oSavedFile.write(b,nStart,nLen); 2}8xY:|@(U
n = nLen; 3+d_5l;m)
} s6.#uT7h
catch(IOException e) iR6w)
{ cgF?[Z+x
e.printStackTrace (); 3|9 U`@
} #0gwN2Nv"L
kSq1Q#Bxq
5fDnr&DR
return n; J-)9>~[E<
} /4lm=ZE/
aEwwK(ny
kCVA~%d7
} <yz&> +9,
+c-?1j
RT$.r5l_@
/* M73d^z
**SiteInfoBean.java x9s1AzM{
*/ YMfjTt@Q
package NetFox; \g<=n&S?
W*/0[|n*
J8:f9a:|M
public class SiteInfoBean { wR*>9LjeG
6im!v<1Qx
~T'Ri=
private String sSiteURL; //Site's URL bL"!z"NA
private String sFilePath; //Saved File's Path 5\\a49k.p
private String sFileName; //Saved File's Name $2lPUQZ<5
private int nSplitter; //Count of Splited Downloading File Uf<hzP
{B,r
]v,>!~8r
public SiteInfoBean() QfHO3Y6h[
{//nSplitter的缺省值为5 MPI=^rc2
//default value of nSplitter is 5 UthH
this("","","",5); 'I8K1Q=/
} f!n0kXVu6U
Ihn+_Hu
y1@*)| r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /Xo8 kC
{ $bd2TVNV:
sSiteURL= sURL; [/iT D=O,
sFilePath = sPath; mf\eg`'4?
sFileName = sName; GfMCHs
this.nSplitter = nSpiltter; TqN4OkCm/
vk]vtjf&%
z-X_O32
} e )?~
Q>[Xm)jr:
UoSzxL
public String getSSiteURL() QFYO_$1Y)
{ x{.+i'
return sSiteURL; H@%Y"iIUP
} W{z{AxS
L/sMAB
QqU>V0y"w(
public void setSSiteURL(String value) xJSK"
{ sN%#e+(=
sSiteURL = value; *dw6>G0U
} DLP G
ZI>')T<@j"
,2C{X+t
public String getSFilePath() gvLzE&V}
{ zIE{U
return sFilePath; TC$)::C1
} U1!#TD)@
<yq kJ
]`,jaD
public void setSFilePath(String value) i`hr'}x
{ SWpvbs.'so
sFilePath = value; CW)JS3}W"
} ?!Bf# "TY
6+s10?
wTw)GV4
public String getSFileName() 5y`n8. (?
{ ^}PG*h|
return sFileName; ~Y.I;EPKt
} vz1yH%~E
j[e<CGZ
A)j',jE&1
public void setSFileName(String value) xS>d$)rIj
{ 2uln)]
sFileName = value; 4,)EG1
} O7of9F~"
{#o0vWS>
p6Ie?Gg
public int getNSplitter() -)Zp"
{ Uzzt+Iwm
return nSplitter; <QcQ.b
} .nG14i7C
6J""gyK.
)5NjwLs
public void setNSplitter(int nCount) tzn+ M0'
{ lH#C:n
nSplitter = nCount; `EJ.L6j$'
} qjrl$[`X:
} CNkI9>L=W`
(<ZpT%2
N3rq8Rk
/* T>cO{I
**Utility.java Am @o}EC
*/ Xvr7qowL
package NetFox; 4v?}K
pcrarj
n;+`%;6
public class Utility { ^S%xaA9
j2GTo~muq
)nM<qaI{
public Utility() \fD)|
{ 5HqvSfq>?
!CGpE=V
Z&![W@m@0N
} A6Vb'Gqv{
S8Ec.]T
//线程睡眠 9(AY7]6
public static void sleep(int nSecond) `Hp=1a
{ gmW-#.
try{ 3[Xc:;+/
Thread.sleep(nSecond); 7]`l"=/z
} JV`"kk/
catch(Exception e) uG){0%nX
{ qOs'Ljx6l
e.printStackTrace (); ~cL)0/j}
} 49iqrP'
} E3"j7y[S
][TA7pDPV
//日志 + \jn$>E
public static void log(String sMsg) vXLGdv::
{ o^8Z cN>
System.err.println(sMsg); vBLs88
} /Y#Q<=X
`37%|e3bQ
B{hV|2
public static void log(int sMsg) 4o69t
{ ]]^r)&pox
System.err.println(sMsg); R}E$SmFg
} mTU[khEmL=
} e,DRQ2AU
X@pcL{T!
me+u"G9I;
/* 8mM`v
**TestMethod.java &WJ;s*
*/ "~:P-]`G
package NetFox; uGU-MC*
>v'@p
8I]rC<O6:
public class TestMethod { VoC|z Rd_
| <bZ*7G
E@J}(76VS
public TestMethod() ZE[NQ8
{ ///xx/weblogic60b2_win.exe 7:'5q]9
try{ ,:6.Gi)|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :2*0Jh3_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @>q4hYF
SiteFileFetch fileFetch = new SiteFileFetch(bean); -_^#7]
fileFetch.start(); Y;1s=B9
} u-u:7VtH0=
catch(Exception e){e.printStackTrace ();} U7xKu75G1
|<2<`3
iit 5IV
} &~'^;hy=
P%y9fU2[
?Ll1B3f
public static void main(String[] args) 95.s,'0
{ eHc.#OA&
new TestMethod(); Im"8+756
} Fgw$;W
} 5 D[`nU}
点击下载更多相关资料