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)); DXQ]b)y+N
} c}s#!|E0v
for(int i=0;i<nEndPos.length-1;i++) *=tA},`\7
{ y6Ez.$M
nEndPos = nStartPos[i+1]; LW#U+bv]Dq
} @bChJl4
nEndPos[nEndPos.length-1] = nFileLength; v+o6ZNX
} dnV&U%fO
} y`z4S,
,L4zhhl!_
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//启动子线程 (?ULp{VPFl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^]Q.V
for(int i=0;i<nStartPos.length;i++) FjMKb
{ ev4_}!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]wfY<Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9_8\xLk
nStartPos,nEndPos,i); 85$ WH
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZXXJ!9-&+J
fileSplitterFetch.start(); ]Inu'p\
} ryqu2>(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qJ2Z5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'Ydr_Ses
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1 ^30]2'_
nEndPos = " + nFileLength); +3sbpl2}
// fileSplitterFetch[nPos.length-1].start(); s3 fQGbU
A8-a}0Gh
N1$PW~)Y
//等待子线程结束 1K(mdL{m5
//int count = 0; Zrj#4E1
//是否结束while循环 0|C !n+OK
boolean breakWhile = false; %m [l/,2x
bdfs'udt9
?uU_N$x
while(!bStop) %dzO*/8cWo
{ EPR85[k
write_nPos(); [Jj@A(Cz
Utility.sleep(500); $$EEhy
breakWhile = true; 1OqVV?oz
o+)y!
<L<^uFB
for(int i=0;i<nStartPos.length;i++) u /DE
{ q*tGlM@R?
if(!fileSplitterFetch.bDownOver) Ep:hObWG)
{ Bs|Xq'1M!;
breakWhile = false; 6J@,bB jVz
break; A&M(a
} (nXnP{yb
} B/o8r4[80
if(breakWhile) C+"c^9[
break; HF"TS*
8aKS=(Z!j
o7WAH@g
//count++; !"&-k:|g
//if(count>4) bC98<if
// siteStop(); =qpGAv_#
} |=KzQY|u
f=VlOd
6 EfBz
System.err.println("文件下载结束！"); fK *l?Hr
} s:_a.4&Y
catch(Exception e){e.printStackTrace ();} g$zGiqzMK
} '.<c[Mp
cd=|P?Bi
g'{?j~g
//获得文件长度 fD3'Ye<R
public long getFileSize() ^,FG9
{ z]-m<#1
int nFileLength = -1; <&2<>*/.y
try{ ww[|| =
URL url = new URL(siteInfoBean.getSSiteURL()); #XB3Wden2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TU58
httpConnection.setRequestProperty("User-Agent","NetFox"); gK@`0/k{
Hc[@c)DH
;yyR_NS
int responseCode=httpConnection.getResponseCode(); +\;Ro18?
if(responseCode>=400) W7gY$\1<&
{ {QaO\{J=
processErrorCode(responseCode); 4; 0#Z^p
return -2; //-2 represent access is error [\Nmm4
} 4]$OO'
K=E+QvSG
H9i7y,[*
String sHeader; 5j$&Zgx51
iSR"$H{
BFhEDkk
for(int i=1;;i++) nB5\ocJ
{ \13Q>iAu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *3!r &iY
//Utility.log(in.readLine()); w!v^6[!
sHeader=httpConnection.getHeaderFieldKey(i); <2L,+
if(sHeader!=null) %{pjC7j#
{ fA]sPh4Uag
if(sHeader.equals("Content-Length")) 023uAaI^3r
{ ~d1=_p:~T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x X[WX#'f
break; L N.:>,
} 6xwjKh:9
} e$WAf`*
else 6({)O1Z
break; Nnr[@^M5
} "Nb2[R
} Y .cjEeL@
catch(IOException e){e.printStackTrace ();} 6 C O5:\
catch(Exception e){e.printStackTrace ();} 9nY|S{L
B$YoglEW:
-mGG:#yP
Utility.log(nFileLength); 'DNxc
IVZUB*wv)b
@$ Nti>
return nFileLength; <8Tp]1z
} d>W#c8X>
5Phsh
q }>3NCh
//保存下载信息（文件指针位置） S.B?l_d^
private void write_nPos() nM:<l}~v{
{ U`8Er48X
try{ mMOgx
output = new DataOutputStream(new FileOutputStream(tmpFile)); XP0;Q;WF}
output.writeInt(nStartPos.length); rQGInzYp
for(int i=0;i<nStartPos.length;i++) i+in?!@G:
{ !Q_Wbu\U
// output.writeLong(nPos); q :~/2<o
output.writeLong(fileSplitterFetch.nStartPos); je2"D7D
output.writeLong(fileSplitterFetch.nEndPos); K]Vp! G
} )=X g
output.close(); W)J5[p?
} P0(LdZH6u
catch(IOException e){e.printStackTrace ();} [tJn!cMs
catch(Exception e){e.printStackTrace ();} tU2#Z=a
} 'J-a2oiM(
#NGtba
On~KTt3Mp
//读取保存的下载信息（文件指针位置） WcS`T?Xa
private void read_nPos() d4ld-y
{ tKcC{
try{ }CMGK{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K1A<m=If
int nCount = input.readInt(); tP*GYWI48
nStartPos = new long[nCount]; <2%9O;bV[
nEndPos = new long[nCount]; dlCiqY:}
for(int i=0;i<nStartPos.length;i++) D29Lu(f
{ `''y,{Fs
nStartPos = input.readLong(); "4Q_F3?_`
nEndPos = input.readLong(); UcD<vg"p
} Ayg^<)JWh
input.close(); #Y3-P
} b=\chCRJJ
catch(IOException e){e.printStackTrace ();} WQ8 "Jj?k6
catch(Exception e){e.printStackTrace ();} WFV'^-4
} *`wz
,%N[FZ`|
xP9h$!
private void processErrorCode(int nErrorCode) febn?|@
{ u/S>*E
System.err.println("Error Code : " + nErrorCode); w xte
} |[mmEYc
<%%)C>l
d0ht*b
//停止文件下载 !X$19"
public void siteStop() H lM7^3(&
{ ~Js kA5h|&
bStop = true; mVYfyLZ,(
for(int i=0;i<nStartPos.length;i++) R"JXWw
fileSplitterFetch.splitterStop(); 3@Fa
Y@#N_]oXj
trrK6(p
} BY[7`@
} t2OBVzK
//负责部分文件的抓取 ok:L]8UN3
**FileSplitterFetch.java B0)|sH
*/ EirZ}fDJzB
package NetFox; #}@8(>T
8q{|nH
L[D+=
import java.io.*; {~FPvmj&
import java.net.*; k+?gWZ\
GiM-8y~
7%? bl
public class FileSplitterFetch extends Thread { FvPWS!H
N[\J#x!U
czu9a"M>X
String sURL; //File URL -ZSN0Xk
long nStartPos; //File Snippet Start Position N6u>V~i
long nEndPos; //File Snippet End Position S2Ez}*plp
int nThreadID; //Thread's ID ,.V<rDwN&
boolean bDownOver = false; //Downing is over ]dJ"_
boolean bStop = false; //Stop identical tA< UkPT
FileAccessI fileAccessI = null; //File Access interface kqj)&0|X
F:P2:s<d-
Fp@>(M#3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F7*)u-4Yn
{ tN\I2wm
this.sURL = sURL; o@.{|j
this.nStartPos = nStart; w}OBp^V^
this.nEndPos = nEnd; cUG^^3!
nThreadID = id; l=l$9H,
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6s~B2t:Y
} dm=?o
ercXw7{
LS9,:!$
public void run() I}|a7,8
{ DW9MX`!Xc
while(nStartPos < nEndPos && !bStop) 'm6bfS^T
{ Lp(`m=;O
C,eP!_O
Nr$78] o9
try{ !DSm[Z1
URL url = new URL(sURL); 82EvlmD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z#Nw[>NN*
httpConnection.setRequestProperty("User-Agent","NetFox"); 1Hr1Ir<KR
String sProperty = "bytes="+nStartPos+"-"; 7rRI-wZ
httpConnection.setRequestProperty("RANGE",sProperty); f"j9C%'*
Utility.log(sProperty); ]*mUc`
Udtz zka
ElB[k<
InputStream input = httpConnection.getInputStream(); ]N'%l]_$
//logResponseHead(httpConnection); m3pDFI
W3>9GY90R
]jVE
byte[] b = new byte[1024]; xl,% Z~[
int nRead; 2P8wvNDG
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w5PscEc
{ %(khE-SW
nStartPos += fileAccessI.write(b,0,nRead); P)f8lU^z
//if(nThreadID == 1) g&F$hm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Y ?n4#J<
} d ([~o
yc3/5]E&
)}N:t:rry
Utility.log("Thread " + nThreadID + " is over!"); vw3[(_MV3_
bDownOver = true; [fT$# '6
//nPos = fileAccessI.write (b,0,nRead); JZxA:dg l
} y3 N[F
catch(Exception e){e.printStackTrace ();} E8#aE\'t
} ~!5Qb{^
} H9ES|ZJs
"~ $i#
ZpOME@9,
//打印回应的头信息 LkzA_|8:D
public void logResponseHead(HttpURLConnection con) e>e${\=,
{ XK/l1E3N
for(int i=1;;i++) j;y(to-e>D
{ u4xtlGt5
String header=con.getHeaderFieldKey(i); )mwwceN
if(header!=null) zw+wq+2"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Hqs-q4G$
Utility.log(header+" : "+con.getHeaderField(header)); gAztdAsLM
else P,)D0i
break; ey[Z<i1
} >M{98NH
} l]wLQqoO
%regt{
F4T!&E%6
public void splitterStop() N]/cBGy
{ Km= Y^x0
bStop = true; )b]wpEFl
} =,N"% }
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sBI/`dGZV
} qQDe'f~
965x_ %
svEe@Kt`
/* ?32~%?m
**FileAccess.java Myg;2.
*//文件访问(定位，写) *`w>\},su
package NetFox; m`8{arz2
import java.io.*; J>T98y/))
nZ'jjS[!
Nk\ni>Du3
public class FileAccessI implements Serializable{ ,ps?@lD
/"A=Yf
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ai?J
RandomAccessFile oSavedFile; 2Ul8<${c{
long nPos; EHf,VIC8
V~/@KU8cH
4V,p\$;
public FileAccessI() throws IOException k -R"e
{ H6K8.
this("",0); mUP!jTF
} ju[y-am$/
"wZvr}xk
4FYV]p8f
public FileAccessI(String sName,long nPos) throws IOException [c1Gq)ht
{ pl@K"PRE
oSavedFile = new RandomAccessFile(sName,"rw"); R8lja%+0$
this.nPos = nPos; ?d?.&nt
oSavedFile.seek(nPos); .J @mpJdY
} ~PyS;L}
Wm"#"l4
ALF21e*n
public synchronized int write(byte[] b,int nStart,int nLen) 9Ca0Tu
{ tpA-IL?KQw
int n = -1; ~Y~M}4
try{ aizws[C
oSavedFile.write(b,nStart,nLen); }[!=O+gO
n = nLen; 0%&}wUjV
} )XSHKPTQ1
catch(IOException e) (c}!gjm
{ yLCMu | +
e.printStackTrace (); X0j>g^b8
} W(ryL_#;
,jz~Np_2
~V?z!3r-)
return n; ]CcRI|g}
} _\k?uUo&,^
;! ?l8R
85dC6wI4K
} Q -$) H;,
^.@%n1I"5y
MRo_An+
/* j`@`M*)GB
**SiteInfoBean.java q!U$\Q&
*/ 5cA:;{z];g
package NetFox; GL9'dL|
d#d&CJAfr
lcpiCZ
public class SiteInfoBean { ZVdQ$
a"O;DYh
p]y.N)a
private String sSiteURL; //Site's URL SfY 5Xgp
private String sFilePath; //Saved File's Path G,<d;:
private String sFileName; //Saved File's Name oBub]<.J
private int nSplitter; //Count of Splited Downloading File {)b
#d[Nm+~ko
& uwOyb
public SiteInfoBean() VR"le&'z"
{//nSplitter的缺省值为5 \X(*JNQ
//default value of nSplitter is 5 SzeY?04zj:
this("","","",5); zXlerQWUv
} jbZTlG
I~~":~&
) 5Ij
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $E;Tj|W
{ ydY(*]
sSiteURL= sURL; \@h$|nb
sFilePath = sPath; nLk`W"irM
sFileName = sName; 6/g 82kqpk
this.nSplitter = nSpiltter; e&!c8\F
8#,_%<?UVy
Au)~"N~p?
} `wj'
R64f0NK.
6Xo"?f
public String getSSiteURL() 1K|F;p
{ x{ `{j'
return sSiteURL; 3]}RjOTU
} M?('VOy)
.C+(E@eyA
P =Q+VIP&
public void setSSiteURL(String value) ^gyI-S(;
{ BaP'y8dVN
sSiteURL = value; tG9C(D`G
} &F7_0iAP(
=)jo}MB
}|8^+V&
public String getSFilePath() 6~{'\Z
{ 6q`)%"4k
return sFilePath; yXEI%2~)
} Qqj9o2
>e-0A
w9"~NK8xzM
public void setSFilePath(String value) ;{R;lF,
{ jHHCJOHB8
sFilePath = value; OA}; pQ9QN
} Ke:EL;*8k
qvWi;
eYkg4O'
public String getSFileName() 5"1wz
{ _e8v12s
return sFileName; Hc|cA(9sh9
} )OQ<H.X
?0sTx6x@
GCr]x '
public void setSFileName(String value) n?D/bXp
{ 6,~1^g*
sFileName = value; 7l*vmF6Z
} Q;q{1M>
hG<[F@d
-nUK%a"(D
public int getNSplitter() b-@9Xjv
{ Lq.2vfA>
return nSplitter; 14uv[z6
} f2Xn!]o
~@@$-,}X
@6R6.i5d
public void setNSplitter(int nCount) p9\*n5{
{ <|G!Qn?2-
nSplitter = nCount; {w"Cr0F,
} }$uwAevP{y
} `0_ Y| 4KB
>mMfZvxl%
Vom,^`}
/* l(F\5Ys
**Utility.java # &5.
*/ \3K7)o^
package NetFox; GA[bo)"
c3#eL
QKVOc,Fp7i
public class Utility { <u# 7K\:
@ %q>Jd
ve.P{;;Ky
public Utility() c\ZnGI\|
{ Ml?KnSb
S&[9Vb
glROT@
} ij3W8i9'
^liW*F"UY
//线程睡眠 L+@X]OW8
public static void sleep(int nSecond) P&:[pPG
{ =^{MyR7
try{ DNqC*IvuzM
Thread.sleep(nSecond); p__N6a
} rL+.3ZO):P
catch(Exception e) { JDD"z
{ H~Uy/22aQy
e.printStackTrace (); (LXYx<
} fshG ~L7S9
} HKO]_; :(
y | I9"R
//日志 /S~ =qodS
public static void log(String sMsg) =h ~n5wQG
{ bd27])n(
System.err.println(sMsg); 1Q9Hs(s
} JqYa~6 C
>YF=6zq.`
8uW%jG3/
public static void log(int sMsg) 2_M+o]Z^
{ }o[<1+W(.
System.err.println(sMsg); q j9q
} 61gyx6v
} DYgB_Iak
uT<<G)v)
9^Web~yi#
/* MI:%Eq
**TestMethod.java d`5AQfL&
*/ ~MYE8xrId
package NetFox; 9~a5R]x2
P-8QXDdr
LH`2Y,E
public class TestMethod { nf&5oE^
$o$WFV+h
/<k5"C%z
public TestMethod() %Kp^wf#o9
{ ///xx/weblogic60b2_win.exe :kwDa a
try{ E GZiWBr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); kFyp;=d:K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Lg#(?tMp,'
SiteFileFetch fileFetch = new SiteFileFetch(bean); {7%HK2='
fileFetch.start(); \\Q){\S
} 3=Rk(%:;
catch(Exception e){e.printStackTrace ();} 5e7\tBab
Q%J,:J
S}]B|Q
} OZ"76|H1`
!g=b=YK
s&$e}yxVO
public static void main(String[] args) Zv-1*hhHf
{ 0E (G1o'
new TestMethod(); !)W#|sys&
} ]Ge>S?u
} ryA+Lli.
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