http断点续传简单实现（java)

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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)); Y[Kpd[)[v
} 8$C?j\J|*
for(int i=0;i<nEndPos.length-1;i++) mv\S1[<T
{ 9 7Mi{Zz
nEndPos = nStartPos[i+1]; 1JWo~E'
} 9 `z^'k&
nEndPos[nEndPos.length-1] = nFileLength; &24$*Oe
} D/]
} )ME'qA3K
2!;U.+(
Ki(
//启动子线程 l"app]uVZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SQJ }$#=
for(int i=0;i<nStartPos.length;i++) U<jAZU[L
{ Gfy9?sa
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c},wW@SF2W
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6P U]I+
nStartPos,nEndPos,i); ^F4h:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bA8RoC
fileSplitterFetch.start(); JPGEE1!B{b
} 1_0\_|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kH}HFl
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :to1%6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", w!~85""
nEndPos = " + nFileLength); DZ5QC aA
// fileSplitterFetch[nPos.length-1].start(); L|N[.V9
q$BS@
^U[yk'!Y
//等待子线程结束 ~fR-cXj"
//int count = 0; UhVJ!NrT
//是否结束while循环 Xw |6 #^
boolean breakWhile = false; *J|]E(
aYd`E4S+
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while(!bStop) bo04y)Iz
{ XYdr~/[HPy
write_nPos(); 9 Z79
Utility.sleep(500); do&0m[x%
breakWhile = true; _5&LV2
*Ph@XkhU
UcxMA%Pw7$
for(int i=0;i<nStartPos.length;i++) >nOzz0,
{ hR(p{$-T
if(!fileSplitterFetch.bDownOver) |+r5D4]e
{ :1,xse
breakWhile = false; AAPfU_: ^
break; 2"C,u V@F!
} I4%25=0?
} ]#t5e>o|
if(breakWhile) p4M7BK:nf
break; 0D:eP``
L qdzqq
WuUT>omH
//count++; hsZ}FLStJ
//if(count>4) qS}pv
// siteStop(); )3A%Un#B
} 6Z7J<0
Z&j?@k,k
|VE*_G
System.err.println("文件下载结束！"); ^dCSk==
} m0_B[dw
catch(Exception e){e.printStackTrace ();} 3P[u>xE
} cu#s}*Ip
$G@^!(
71inHg
//获得文件长度 "R9^X3;
public long getFileSize() @(_f}SgfE
{ tDwj~{a~
int nFileLength = -1; A.@Af+
try{ >S=,ype~G
URL url = new URL(siteInfoBean.getSSiteURL()); 9d1 Gu"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7UA|G2Zr
httpConnection.setRequestProperty("User-Agent","NetFox"); j3yz"-53e
ZK8I f?SD
Cv;\cI"&
int responseCode=httpConnection.getResponseCode(); ga+Z6|t
if(responseCode>=400) w\2yippI
{ qk=0ovUzg
processErrorCode(responseCode); 6kM'f}t[C
return -2; //-2 represent access is error ;gmfWHB<
} Y%A KN
g"o),$tm
95X!{\
String sHeader; k=8LhO
~sUWXw7~
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for(int i=1;;i++) gg}^@h&?
{ Z5%TpAu[
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); r(ufyC&
//Utility.log(in.readLine()); elzKtVw
sHeader=httpConnection.getHeaderFieldKey(i); 2-!n+#Cdf
if(sHeader!=null) 2B=''W
{ <rAk"R^
if(sHeader.equals("Content-Length")) jFThW N
{ iz pFl@WS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .?CumaU
break; ps=+wg?]
} 6h_OxO&!U
} \QKr2|
else kx_PMpc
break; i1JWdHt
} |nTZ/MXbw
} Y\1XKAfB
catch(IOException e){e.printStackTrace ();} ` "JslpN
catch(Exception e){e.printStackTrace ();} V- HO_GDo
[osm\w49
'-k~qQk)6
Utility.log(nFileLength); ?B`Yq\L)
*N|s+
y/}ENUGR
return nFileLength; {pof=G
} y$^.HI02jP
OP}8u"\Z
*S$`/X
//保存下载信息（文件指针位置） ;UB$Uqs6
private void write_nPos() }4M4D/=
{ C;_*vi2u
try{ )ls<"WTC.
output = new DataOutputStream(new FileOutputStream(tmpFile)); )TFBb\f>v
output.writeInt(nStartPos.length); A7X-),D
for(int i=0;i<nStartPos.length;i++) |~I-
{ A}cGag+sp
// output.writeLong(nPos); {f }4l
output.writeLong(fileSplitterFetch.nStartPos); Ap[}[:U
output.writeLong(fileSplitterFetch.nEndPos); qmJ^@dxs
} 5{uK;Vxse
output.close(); F9&ae*>,
} ={a_?l%
catch(IOException e){e.printStackTrace ();} Fkvf[!Ci
catch(Exception e){e.printStackTrace ();} dzbFUDJ
} af>^<q
nb30<h
0en Bq>vr
//读取保存的下载信息（文件指针位置） _xmS$z)TO
private void read_nPos() i-YSt5iq
{ :Z R5<Y>
try{ pba`FC4R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J$D/-*/@
int nCount = input.readInt(); _O$7*k
nStartPos = new long[nCount]; Puq
nEndPos = new long[nCount]; )azK&f@tR|
for(int i=0;i<nStartPos.length;i++) W<c95QD.
{ |?gO@?KDZ
nStartPos = input.readLong(); N<N uBtkA
nEndPos = input.readLong(); NI^jQS M]
} my}l?S[2d@
input.close(); t_"]n*zk1
} &y+)xe:&S
catch(IOException e){e.printStackTrace ();} r.ib"W#4
catch(Exception e){e.printStackTrace ();} U)JwoO
} H/^t]bg,
sK/Z'h{|
@Rw]boC
private void processErrorCode(int nErrorCode) yEPkF0?
{ t%fcp
System.err.println("Error Code : " + nErrorCode); (7*((
} B.#.gB#C
eJy}W /
>4G~01
//停止文件下载 Q3'L\_1L
public void siteStop() <HfmNhI85(
{ <-(n48
bStop = true; \sEH)$R'
for(int i=0;i<nStartPos.length;i++) >mW*K _~
fileSplitterFetch.splitterStop(); e6i m_ Tk
s= bP@[Gj
o:c:hSV
} MC~<jJ,
} \"|7o8
//负责部分文件的抓取 vUR@P -
**FileSplitterFetch.java 3Hi[Y[O`%P
*/ oIv\Xdc81
package NetFox; z5g4+y,
N Wf IRL
RQ;}+S
import java.io.*; gkFw=Cd
import java.net.*; 3y}8|ML
D16w!Mnz{K
2I>`{#fV
public class FileSplitterFetch extends Thread { r:U/a=V
MWI7u7{
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String sURL; //File URL .!)i
long nStartPos; //File Snippet Start Position a^7HI,
long nEndPos; //File Snippet End Position ZkmYpi[
int nThreadID; //Thread's ID *q*$%H
boolean bDownOver = false; //Downing is over eE5j6`5i
boolean bStop = false; //Stop identical h1+y.4
FileAccessI fileAccessI = null; //File Access interface NRMEZ\*L
+GL[uxe"
Ya29t98Pk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Jy P$'v~
{ >c=-uI
this.sURL = sURL; D zdKBJT+
this.nStartPos = nStart; K)#6&\0tT
this.nEndPos = nEnd; ld[BiP`B2V
nThreadID = id; "Ky&x$dje
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |lMc6C
} B4eV$~<
S#b)RpY
NJmyp!8
public void run() >^GAfvW
{ "V<WC"
while(nStartPos < nEndPos && !bStop) NArr2o2
{ xp F(de
v!j%<H`NI
eL1)_M;{
try{ P*/ig0_fM
URL url = new URL(sURL); 9;ie[sU:u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); fbW<c`LH
httpConnection.setRequestProperty("User-Agent","NetFox"); 30bdcDm,
String sProperty = "bytes="+nStartPos+"-"; l9z{pZ\KM
httpConnection.setRequestProperty("RANGE",sProperty); [8'^"
Utility.log(sProperty); NL-V",gI-~
Y'Yu1mH)
ttY[\D&ZS
InputStream input = httpConnection.getInputStream(); &HtG&RvQf
//logResponseHead(httpConnection); *YP:-
8 Y))/]R
|4!G@-2V:I
byte[] b = new byte[1024]; ltlnXjRUv
int nRead; OWZ;X}x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .RpWE.C
{ w"q^8"j!
nStartPos += fileAccessI.write(b,0,nRead); :_:o%
//if(nThreadID == 1) """pe+Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); KvumU>c#A
} P=m l;xp
9)$gD
H`nd |
Utility.log("Thread " + nThreadID + " is over!"); *})Np0k
bDownOver = true; !X\aZ{}Q
//nPos = fileAccessI.write (b,0,nRead); dZ x
} ->'xjD
catch(Exception e){e.printStackTrace ();} '[p0+5*x
} /Zg4JQ~
} ,VZ<r5NT
+&[X7r<
wg^'oy
//打印回应的头信息 = ,c!V
public void logResponseHead(HttpURLConnection con) -/R?D1kOq
{ "DSRyD0M
for(int i=1;;i++) 9P*p{O{_
{ 1"No~/_
String header=con.getHeaderFieldKey(i); $9ys! <g
if(header!=null) H^JFPvEc
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KeWIC,kq
Utility.log(header+" : "+con.getHeaderField(header)); ,p V3O`z
else I^m9(L4%
break; I\f\k>;
} y'_2|5!Qs
} 0Vj!'=Ntv
p:xVi0
r85j/YK
public void splitterStop() .xe+cK
{ %UB+N8x`a
bStop = true; +TN*6V{D
} X<d`!,bn@
<tv"I-2
\J6&Z13Q
} )D"2Q:
@;Xa&*
cG!dMab(
/* c3N,P<#
**FileAccess.java ~8EzK_c
*//文件访问(定位，写) o)M<^b3KO
package NetFox; Wb;D9Z
import java.io.*; =QhK|C!$A
MS& 'Nj
c3J12+~;
public class FileAccessI implements Serializable{ <%m$ V5h
ZL'krV
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Rw|P$dbu
RandomAccessFile oSavedFile; +0M0g_sk
long nPos; S6{u(=H
Dyh|F\T
cG5u$B
public FileAccessI() throws IOException Hu"TEhW(2
{ Ub`vf4EB
this("",0); w~>tpkUB
} V L;<+C~
%18%T{|$e
Z<`:xFy(
public FileAccessI(String sName,long nPos) throws IOException cQq78Lo
{ #NWS)^&1b
oSavedFile = new RandomAccessFile(sName,"rw"); qsdgG1<
this.nPos = nPos; a7"Aq:IjU
oSavedFile.seek(nPos); bf6:J `5Z
} ?L6pB]l8b
< mp_[-c
v8>bR|n5
public synchronized int write(byte[] b,int nStart,int nLen) 0?=a$0_C
{ U<wM#l P|Z
int n = -1; Sw`+4 4
try{ ;Mz7emt
oSavedFile.write(b,nStart,nLen); \`-a'u=S
n = nLen; 40%<E
} c.}#.-b8
catch(IOException e) z7R2viR[
{ "X\6tl7a|
e.printStackTrace (); H4uHCkj
} fy={
7,FhKTV1/
5?|yYQM0tK
return n; hx8.
} !CR#Fyt+9
&[kFl\
%wN*Hu~E
} 5-POYug
C'a#.LM
lbMok/a2o
/* iIc/%< ;
**SiteInfoBean.java %nyZ=&u
*/ u|75r%p>
package NetFox; t"X^|!hKIF
[!U! Z'i
0D&-BAzi
public class SiteInfoBean { b ; U
J6Nhpzp
&[_D'jm+S0
private String sSiteURL; //Site's URL U|+c&TY
private String sFilePath; //Saved File's Path 64t:
private String sFileName; //Saved File's Name fiW2m=h_
private int nSplitter; //Count of Splited Downloading File 6/&|)gW',
!G;|~|fMV
r+,JM L
public SiteInfoBean() t_id/
{//nSplitter的缺省值为5 d?N[bA
//default value of nSplitter is 5 !nTI(--
this("","","",5); vo^2k13
} K?*p|&Fi?8
g:Ry.=F7W
h=dFSK?*D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ?s[!JeUA
{ rbI 7 3'
sSiteURL= sURL; 83_vo0@<6
sFilePath = sPath; C9n*?Mk:
sFileName = sName; TsY nsLQY
this.nSplitter = nSpiltter; |J:m{
r)oR`\7
BF /4
} -V=,x3Zew
X-`PF
+7r?vo1
public String getSSiteURL() afd.v$63
{ Qb'Q4@.
return sSiteURL; -lb%X3`
} H6<3'P
u^( s0q
WP !u3\91
public void setSSiteURL(String value) Bs^p!4=
{ ICzcV };$
sSiteURL = value; UVgDm&FF
} S0?e/VWy
\ \gAa-}:
-d^c!Iu|
public String getSFilePath() p$a+?5'Q
{ >f(M5v(D\
return sFilePath; q>[}JtXK
} (Ji=fh+
SyIi*dH
Nh1, w
public void setSFilePath(String value) *kt%.wPJ
{ fr8hT(,s)
sFilePath = value; Tfw5i,{
} cQ(,M
.cB>ab&
Cw h[R
public String getSFileName() scZ&}Ni
{ <%S[6*6U
return sFileName; o^Qy71Uj
} fkD-mRKw
';I(#J6
CIAKXYM
public void setSFileName(String value) +{WZpP},v
{ jm,:jkr
sFileName = value; :b<<
} 0iVeM!bM
}[]1`2qD
&;%,Axc
public int getNSplitter() n\u3$nGL1`
{ ~{q; -&
return nSplitter; i7\MVI8
} ;TboS-Y
56H~MnX
oWBjPsQ
public void setNSplitter(int nCount) 0r]-Ltvl?}
{ na3lbwq
nSplitter = nCount; Ie4Xk
} bDnT><eH
} 4v.i!U# {
,$"T/yYer
&"clBRVg
/* ai;-_M+$
**Utility.java 7A{,)Y/w ^
*/ p)s*Cw
package NetFox; DS0:^TLI
9a]h;r8,9z
O[z-K K<
public class Utility { 3#Xv))w1
#xt-65^
ltOsl-OpR
public Utility() *yN#q>1
{ D9\ EkX
}a!c
8jz7t:0
} /<CgSW}
lLN5***47J
//线程睡眠 [y(<1]i-a
public static void sleep(int nSecond) T)MZ`dM
{ ab>>W!r@!
try{ LNF|mS\+D
Thread.sleep(nSecond); {emym$we
} o= &/;X
catch(Exception e) iy [W:<c7j
{ z W*Z
e.printStackTrace (); ,b74m
} (4C_Ft*~j
} ,9~qLQ0O
8!qzG4F/
//日志 !uAqY\Is
public static void log(String sMsg) {r_x\VC=p
{ :Kk+wp}f#
System.err.println(sMsg); $pj;CoPm
} eV(
4*?i!<N9
a4Y43n
public static void log(int sMsg) Og2G0sWRf
{ d+%Rg\v
System.err.println(sMsg); SlD7 \X&~
} 4Vv$bbu+
} T:S[[#f{5
Ummoph7_@
iV.j!H7o
/* @}hdMVi
**TestMethod.java I?KGb:]|
*/ Q,nXc
package NetFox; +]0/:\(B
1a'0cSH
2I0Zr;\f
public class TestMethod { @c;:D`\p1C
@H8CU!J
cR!Mn$m
public TestMethod() %D E_kwL
{ ///xx/weblogic60b2_win.exe A8j$c~
try{ @^,9O92l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); jGtu>|Gj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 73kI%nNB
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5]Y?NN,GR
fileFetch.start(); ; e)vk|
} hGj`IAW
catch(Exception e){e.printStackTrace ();} z;PF%F
T;{"lp.
G>S3?jGk
} nOq`Cwh9
PbY=?>0z
\Z$MH`_nu
public static void main(String[] args) NkYC(;g
{ 2t:CK
new TestMethod(); aThvq%;
} H*h4D+Kxv
} AzFS6<_
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