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)); {I{ 0rV
} wiN0|h>,
for(int i=0;i<nEndPos.length-1;i++) >j?5?J"
{ )U\i7[k>
nEndPos = nStartPos[i+1]; ]ae(t`\l^
} !`{?qQ[=
nEndPos[nEndPos.length-1] = nFileLength; XVs]Y'*x
} &[d'g0pF
} p cLKE ZK
31G:[;g
\lK?f]qJq
//启动子线程 L~&S<5?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,Q"'q0hM=
for(int i=0;i<nStartPos.length;i++) k[x-O?$O@
{ K&[0`sH!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `:C1Wo^<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n5QO'Jr%[
nStartPos,nEndPos,i); Z|qI[uiO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); li*S^uSF
fileSplitterFetch.start(); .B`$hxl*0c
} S|=)^$:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?nc:bC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =CQfs6np:N
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", =i)%AnZ^9
nEndPos = " + nFileLength); \92M\S
// fileSplitterFetch[nPos.length-1].start(); %B@NW2ZQ[
P`Zon
/gu VA
//等待子线程结束 "(mJupI
//int count = 0; ;2kQ)Bq"
//是否结束while循环 2VV>?s
boolean breakWhile = false; (XOz_K6c%K
+C`!4v\n
1EV bGe%b
while(!bStop) v/ry" W
{ 7@{%S~TN
write_nPos(); phDIUhL$z
Utility.sleep(500); 1sXCu|\q
breakWhile = true; "==c
Xq1#rK(
IgbuMEfL
for(int i=0;i<nStartPos.length;i++) 'fn}I0Vc
{ t]&.'n,
if(!fileSplitterFetch.bDownOver) j)@W1I]2#
{ Ny"9!3V
breakWhile = false; l4RqQ+[KA;
break; X0j\nXk
} 8ve-g\C8 H
} v o:KL%)
if(breakWhile) >"/TiQt
break; vJ0v6\
s$(%]~P
S\Z*7j3;M
//count++; S[L@8z.Sj
//if(count>4) 4<s;xSCL
// siteStop(); \gP?uJ
} l i<9nMZ<
0@_8JB ?E
$l,U)
System.err.println("文件下载结束！"); GIlaJ!/
} z"6o|]9I
catch(Exception e){e.printStackTrace ();} \0|x<~#j'
} HP*)^`6X
w(HVC
54z`KX 73
//获得文件长度 i<S\x
public long getFileSize() -(57C*#ap
{ g;Fdm5Q
int nFileLength = -1; /,:cbpHsu
try{ /%m?D o
URL url = new URL(siteInfoBean.getSSiteURL()); H'S~GP4D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m&AbH&;
httpConnection.setRequestProperty("User-Agent","NetFox"); Cnpl0rV~5
{ZUk!o>m@
-F`gRAr-
int responseCode=httpConnection.getResponseCode(); .x$V~t
if(responseCode>=400) E`N`
{ yMW3mx301j
processErrorCode(responseCode); -}@C9Ja[?
return -2; //-2 represent access is error O4-#)#-)S~
} xpa+R^D5G
q!&:y7O8
N_D=j6B
String sHeader; j&[lDlI_
kXV
e[k\VYj[
for(int i=1;;i++) u9;3Xn8
{ e|A=sCN-
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); a/E(GQ,,
//Utility.log(in.readLine()); CV|Ae [
sHeader=httpConnection.getHeaderFieldKey(i); ~a=]w#-KD
if(sHeader!=null) + o< 7*
{ p!DdX
if(sHeader.equals("Content-Length")) o<b
{ djf8FNnn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fwtsr>SV
break; wOUCe#P|r
} ++2a xRl
} qw4wg9w5p
else UHY)+6qt]
break; 2;:]Q.g
} (QFZM"G
} i_Lu
catch(IOException e){e.printStackTrace ();} Iv7BIK^0
catch(Exception e){e.printStackTrace ();} V13^SVM
(O ;R~Io
lN.&46 e
Utility.log(nFileLength); f:q2JgX
QdZHIgh`i
H{P*d=9v
return nFileLength; /L,iF?7
} %_]O|(
7OZ0;fK
TbMlYf]It
//保存下载信息（文件指针位置） +SV!QMIg
private void write_nPos() "`K73M,c?9
{ ;|rFP
try{ cmf*BkS
output = new DataOutputStream(new FileOutputStream(tmpFile)); O,@QGUoA
output.writeInt(nStartPos.length); F[ ^ p~u{
for(int i=0;i<nStartPos.length;i++) ,vi6<C\
{ (4l M3clF
// output.writeLong(nPos); bN*zx)f
output.writeLong(fileSplitterFetch.nStartPos); }2y"F@{T
output.writeLong(fileSplitterFetch.nEndPos); '&/Y}]
} 8QFRX'i
output.close(); 5;{*mJ:F
} Wi)N/^;n
catch(IOException e){e.printStackTrace ();} @)ozgs@e
catch(Exception e){e.printStackTrace ();} Wbmqf s
} vO{[P#L}
1iY?t
k:s86q
//读取保存的下载信息（文件指针位置） -% B)+yq>
private void read_nPos() MoC/xF&
{ NnZ_x>R
try{ t I+]x]m+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^YPw'cZZ&
int nCount = input.readInt(); #$t93EI
nStartPos = new long[nCount]; ZCuh^
nEndPos = new long[nCount]; ng2yZ @$
for(int i=0;i<nStartPos.length;i++) 78z/D|{"
{ Se/]J<]
nStartPos = input.readLong(); M>Ws}Y
nEndPos = input.readLong(); BGB.SN#q+
} 9&c *%mm
input.close(); P>6wr\9i[
} >m9ge`!9
catch(IOException e){e.printStackTrace ();} %]DJ-7 xE
catch(Exception e){e.printStackTrace ();} UJX5}36
} tIX|oWC$q
Wm58[;%LTw
vP<8,XG
private void processErrorCode(int nErrorCode) \]/6>yT
{ $_Lcw"xO
System.err.println("Error Code : " + nErrorCode); \4q1<j
} fwyz|>H_Y(
j"+R*H(#
Yi"jj;!^S
//停止文件下载 9T;l*
public void siteStop() QEL3b4Vm
{ !P:~oo=
bStop = true; YKj PE
for(int i=0;i<nStartPos.length;i++) vn5]+-I
fileSplitterFetch.splitterStop(); ! F&{I
Q5v_^O<!
bF3}L=z
} o2(*5*b!@e
} o@\q6xl.
//负责部分文件的抓取 mK7egAo
**FileSplitterFetch.java !Ys.KDL
*/ x:Tm4V{
package NetFox; u-Ip*1/wp
Qgv-QcI{
8J7<7Sx
import java.io.*; d 'wWj
import java.net.*; /?8rj3
| \JB/x
UD r@
public class FileSplitterFetch extends Thread { Jqi^Z*PuX
Q,f5r%A.
r`'n3#O*
String sURL; //File URL 2:S 4M.j
long nStartPos; //File Snippet Start Position z+@Jx~<i
long nEndPos; //File Snippet End Position ~|)'vK8W
int nThreadID; //Thread's ID mm<rdo(`
boolean bDownOver = false; //Downing is over ?To r)>A'
boolean bStop = false; //Stop identical <N;HB&mr
FileAccessI fileAccessI = null; //File Access interface B1gBvss
RIl+QA
Y_&)>;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :-.bXOB(
{ uod&'g{N
this.sURL = sURL; 5AT[1@H(_
this.nStartPos = nStart; ?\Jl] {i2
this.nEndPos = nEnd; Ik|nL#JH]
nThreadID = id; E>SLR8!Cv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ugt|'i
} "(d7:!%
)Wm:Ilq
1vBXO bk
public void run() pEE.%U
{ F4Gv=q)Z
while(nStartPos < nEndPos && !bStop) '`Z5.<n7p
{ {o[*S%Z"
Cc,,e`
rt\4We,7
try{ B[O1^jdO
URL url = new URL(sURL); #}!Ge
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {)0"?$C_H
httpConnection.setRequestProperty("User-Agent","NetFox"); !_gHIJiq}
String sProperty = "bytes="+nStartPos+"-"; +Te;LJP
httpConnection.setRequestProperty("RANGE",sProperty); sk_Q\0a
Utility.log(sProperty); t/aT
Bq]eNq
+K%4jIm
InputStream input = httpConnection.getInputStream(); e[7n`ka '
//logResponseHead(httpConnection); Xj<B!Wn*Xb
8FThu[
v5GV"qY
byte[] b = new byte[1024]; q>*+.~
int nRead; 8?O6IDeW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @ zE>n
{ x;Jy-hMNl
nStartPos += fileAccessI.write(b,0,nRead); xV4 #_1(
//if(nThreadID == 1) _ZfJfd~
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rBZ0(XSZQ
} i7w>Nvj]
sc^TElic
7x^P74
Utility.log("Thread " + nThreadID + " is over!"); 58Fan*fO
bDownOver = true; z\8Kz ]n~
//nPos = fileAccessI.write (b,0,nRead); F\Gi;6a
} #yk m
catch(Exception e){e.printStackTrace ();} ]QS?fs Z
} +idj,J|
} *s9 +
'lym^^MjL+
yb#NB)+E@
//打印回应的头信息 -qBrJ1*
public void logResponseHead(HttpURLConnection con) Vx^+Z,y&QP
{ E8~Bp-G)
for(int i=1;;i++) !$x9s'D
{ 39QAj&
String header=con.getHeaderFieldKey(i); C0X_t
if(header!=null) _kb $S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); A-&C.g
Utility.log(header+" : "+con.getHeaderField(header)); io$!z=W
else r-+.Ax4L"
break; .j}dk.#h
} :U>o;
} Dxu2rz!li-
]N^a/&}*
G:QaWqUb
public void splitterStop() @""aNKA^r>
{ 7p(^I*|
bStop = true; ^6 F-H(
} |*Dklo9{
%W=S*"e-
<8>gb!DG
} MkG3TODfHB
X9#;quco@
1O0o18'
/* r(IQ)\GR
**FileAccess.java 'dp3>4
*//文件访问(定位，写) Q&;dXE h
package NetFox; POQRq%w
import java.io.*; SXn1v.6
c@%:aiEl
S$Tc\/{
public class FileAccessI implements Serializable{ ,25Qhz]
`Pv[A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R g7 O
RandomAccessFile oSavedFile; s('<ms
long nPos; cWSiJr):r
~r6qnC2
Tp&03
public FileAccessI() throws IOException C#`VVtei
{ Lf|5miO
this("",0); #y"EhwF
} Re**)3#gn
b/='M`D}#G
n0:Y*Op
public FileAccessI(String sName,long nPos) throws IOException JB~79Lsdz
{ NWuS/Ur`9
oSavedFile = new RandomAccessFile(sName,"rw"); "MD
this.nPos = nPos; UUGwXq96i
oSavedFile.seek(nPos); %Uj7g>
} -ckk2D?
uI^E9r/hB
_6v|k}tW'Y
public synchronized int write(byte[] b,int nStart,int nLen) 4i>sOP3 B
{ \Jr ta
int n = -1; |-l)$i@
try{ st"uD\L1p:
oSavedFile.write(b,nStart,nLen); /l-lkG5
n = nLen; y| *X
} =^m,|j|d>4
catch(IOException e) h=uwOi6}
{ :gMcl"t--
e.printStackTrace (); y<bA Y_-[
} A`x_M!m
|[/[*hDZ9
3VZeUOxY\W
return n; ,*SoV~
} kYBy\
hce *G@b
$gU6=vN1#
} ^W|B Xxo
#%t&f"j2
[;3` Aw
/* zWYm*c"n\
**SiteInfoBean.java zyyt`
*/ $Cw> z^}u
package NetFox; !e?g"5r{Bv
t{n|!T&
D7.|UG?G
public class SiteInfoBean { .}W#YN$
JX%B_eUlAs
,;LxFS5\
private String sSiteURL; //Site's URL {//;GC*
private String sFilePath; //Saved File's Path x9Veg4Z7
private String sFileName; //Saved File's Name /g}2QmvH
private int nSplitter; //Count of Splited Downloading File f$Fa*O-
cn1UFmT
gPs%v`y)*D
public SiteInfoBean() vovc,4}
{//nSplitter的缺省值为5 7'g'qUW+~
//default value of nSplitter is 5 byz2u
this("","","",5); S&]AIG)
} UruD&=AMK
es}j6A1
f;1DhAS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =SJwCT0;
{ QJ2V&t"3
sSiteURL= sURL; j{00iA}
sFilePath = sPath; !;'#fxW[
sFileName = sName; >*#clf;@p
this.nSplitter = nSpiltter; *k)v#;B
i7g+8zd8d
%Q9 iR5?
} NV 6kj=r
EugQr<sM#
X=O}k&
public String getSSiteURL() /5 rWcX
{ tmM8YN|
return sSiteURL; gd~# uR\
} zrD];DP
&?\'Z~B4
^MJTlRUb
public void setSSiteURL(String value) 1<Fh aK
{ hs'J'~a
sSiteURL = value; wfr+-
} g wM~W
kkfwICBI
Q2[@yRY/z
public String getSFilePath() N\ nr
{ So &c\Ff
return sFilePath; n{oRmw-
} +3B^e%`NPm
"YLH]9"=
*LnY}#
public void setSFilePath(String value) e_3KNQ`kA
{ A#&Q(g\YE
sFilePath = value; (x7AV$N
} #P:o
iwb]mJUA
+[l52p@a
public String getSFileName() UO%VuC5B
{ dxm_AUM
return sFileName; 1QHCX*_
} }2qmL$
d0(GE4+/
BPAz.K Q
public void setSFileName(String value) q0Rd^c
{ -]=-IiC#
sFileName = value; rN3i5.*/t
} sDV*k4
utk'joo
F$a?} }
public int getNSplitter() V,>_L
{ qta^i819
return nSplitter; /+pPcK
} =X6+}YQ"
u@!iByVAg
U'IJwGRP
public void setNSplitter(int nCount) W`zY\]
{ #@h3#IC
nSplitter = nCount; (GnwK1f
} ).+!/x
} JI1O(
QW~-+BD
9:tvkl
/* n ,<`.^
**Utility.java 8 jom)a
*/ =}@m$g
package NetFox; }hT1@I
z!09vDB^
'8g/^Y@
public class Utility { k:(i sKIA
&&C]i~
}NQx2k0
public Utility() Ydv\a6
{ [.e Y xZ{=
:sT\-MpQvn
W!a~ #R/r-
} i?^Cc\gH
|.D_[QI
//线程睡眠 5u ED
public static void sleep(int nSecond) ~<0!sE&y
{ 6km{= ```
try{ 'TPRGX~&
Thread.sleep(nSecond); ?L|Jc_E
} Ck,.4@\tK
catch(Exception e) kqYvd]ss
{ ,WF)GS|7V
e.printStackTrace (); _#c^z;!
} Uk5O9D0 He
} 5- Q`v/w;
H!dUQ
//日志 MxiU-
public static void log(String sMsg) A@/DGrZX
{ G@Dw
System.err.println(sMsg); 0`X%&
} 1\d$2N"
Yuy7TeJRx
[0GM!3YJ7
public static void log(int sMsg) l'~]8Wo1
{ #80*3vi~F
System.err.println(sMsg); zT}Qrf~
} ^iJMUV|
} qlUYu"`i
5 Vm |/
A%u@xL,_
/* 06bl$%
**TestMethod.java +4emkDTdR
*/ U4#[>*
package NetFox; mY9u/;dK
{aq\sf;i{
NEQcEUd?
public class TestMethod { b~ ?TDm7
R6 wK'
nLq7J:
public TestMethod() ?V_Qa0k
{ ///xx/weblogic60b2_win.exe "m]"%MU78
try{ zO>N3pMv
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); to Ei4u)m
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); (^g?/i1@d
SiteFileFetch fileFetch = new SiteFileFetch(bean); !x.^ya
fileFetch.start(); 9E_C u2B
} 3uwZ#
catch(Exception e){e.printStackTrace ();} $1(u.Ud
tkdhT8_
9/w'4bd
} MBCA%3z08
vCwDE~
uPe4Rr
public static void main(String[] args) lh*m(
{ GK}?*Lfs
new TestMethod(); z)5n&w S
} wxZnuCO%H8
} fiTMS:
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